I would never suggest a sectional in a first time rental A sofa and 2 chairs are always a better choice but especially in a space that is not your own. I think your DR set will be perfect in that small DR.I think you need to decide exactly what your favorite style is and then get some basic pieces like the sofa and chairs in a simple design and use pillows and accessories to add flair.The rug is a bit traditional but by using the colors from it for pillows that bohemian look can happen. I would not go crazy with Boho it can become really awful if taken too far.You could do something like this and if you get tired of that look it is easy to change pillows to something like MCM.

All your choices are nice and I think some art, pillows and accessories will give you the look that you like. Make sure your rug is big enough for the space. You want all the furniture on the rug or touching the rug.

In general, sectionals severely limit your ability to arrange the furniture. For instance, where are you going to fit your new coffee table? Your chaise isn't going to allow you to center it in front of the sofa.

The other issue is that many spots on a sectional are not comfy for guests. Especially the middle area and the chaise area. So, you end up with a piece of furniture that is taking up more space but you have fewer seating options.

It is hard not be be influenced by what you see in stores and on pinterest. The best advice is to go slow and not try to fill the room all at once. The most interesting spaces reflect the homeowner's personality and are decorated with things collected over time.

When you go to Home Goods and fill your cart with decor items from the mcm or farm house area, your space ends up looking like a Home Goods display.

Most of your choices are actually pretty neutral and you have good decorating instincts. Right now you have just about everything you need to live comfortably in the space. I would look for a couple of lamps and then take a decorating break until move in. If you see something you LOVE between now and then, by all means get it. But don't buy things just to fill up the apartment.

I think you could take advantage of the beautiful rug to use a mix of patterns, textures and colours, and some things that at least look hand-made. Pick up on the Persian aesthetic, add a bit of humour.

https://www.pillowdecor.com/Tangga-Orange-Throw-Pillow-20X20-p/vb1-0041-03-20.htm

https://intl.target.com/c/throw-pillows-home-decor/farmhouse/-/N-5xttpZbaha0s4y744?disable_sapphire=true&;

https://www.aliexpress.com/w/wholesale-orange-curtains.html

https://www.ebay.com/itm/antique-moroccan-engraved-carved-silver-plated-brass-bowl-vase-5-5-d-x-5-t/201535291063?hash=item2eec707eb7

https://www.amazon.com/Sofia-Ivory-Ceramic-Table-Lamp/dp/B00F0TDZKS/ref=br_lf_m_9dmwojcpmr956o8_img?_encoding=UTF8&s=hi

https://www.wayfair.com/decor-pillows/pdp/cyan-design-bird-wire-figurine-vyq6548.html

I wouldn't worry, really. Your pieces seem easy to take in many directions, they'll work well together. Add lots of organic elements, textiles in patterns that speak to you and in colors that you love and that correspond with the rug, chair, etc..plants of course. Add patterns, rougher-looking materials such as knitted nubby fabrics, and clay pottery for example, and baskets(that can hold something useful in them). In general, strive for accessories to be useful. Throws and pillows-not too many yet very comfy indeed. Baskets-one can keep there stuff. Ceramics-can hold plants and flowers or pens and pencils. Whatever you buy-use it. You're right in your thinking about lights, mirrors..these can be anything from simple to elaborate, and still work, and change the mood of your rooms wherever you want to take it. Look at many..what are the ones you constantly want to see more, in a day, in a week, in a month? don't hurry, and you'll be all fine. On the other hand, do hurry when you're extremely sure something grabs your heart. That can happen too, especially with art. Don't follow "styles" with art-needs to be meaningful to you. Even if you'll feel it doesn't want to be on your wall X-it's okay. Put it where it wants to be, patiently wait for another piece you're in love with. It doesn't need to cost much, at all. It can be found on flea market or on art fair or in vintage store or on garage sale. Or you can go to numerous sites dedicated to art or containing art (Etsy, eBay, Everything But The House, Chairish..you name it) and fall in love with something. It can also be that your art will be photography, maps, baskets, plates, textiles.."art is what we frame", as somebody said.

Don't hang on to a very strict definition of style-most of us are a bit of this and a bit of that. The trick is to find the common denominator of things that speak to you. Everybody will have theirs. Sometimes it's easy to explain, sometimes harder. The moment you find your explanation you find your common thread and everything that enters your house will be tied by this thread. It'll be like a spider web)) of sorts.

Do figure out what is you prefer the most (which does seem to be mcm for the most part-not all of your pieces are, say sectional is what I'd call contemprary transitional, if such term exists? but the pieces you've picked are really versatile ones..you love the beauty of natural wood, and unfussy yet a bit softer lines). Then add to it slowly other elements, just watch the overall balance.

I do recommend-if you haven't stumbled upon this book yet-"The New Bohemians" by Justina Blakeney https://www.amazon.com/New-Bohemians-Cool-Collected-Homes/dp/1617691518

She showlights there quite a few interiors, from much more understated organic modern to more rustic to very vibrant and maximalist, and many in between (the book is actually divided by chapters -different approaches to spaces-with gorgeous illustrations and interviews with homeowners, and some easy DIY projects), so one can see that Bohemian for example can be done in different ways, some sensibilitities will be shared, the vibe will signal something similar to you, yet every home can sway a bit more modern, or more traditional, or be on a quieter side, or be very bold. If nothing else-that's a very inspiring book.