You need curtains in this room, and open those blinds! Guest book is way too small. Find some art you like for that wall or a piece of furniture with a mirror over it.

I agree with Anglo about everything. Find some pretty curtains, and make sure that the curtain rod is long enough so that when the curtains are open, they are not obstructing the window at all. Do you need blinds at all if you have curtains? If you need blinds, what about bamboo matchstick blinds instead?

Yes also to replacing the guest book (which to me seems like an odd choice in a dining room) with a larger piece of art or a mirror. Is there room on that wall for a narrow but wide console/buffet? Because if so, you could also add some buffet lamps.

You could leave the guest book up and do a gallery wall around it with other pictures making it an interesting focal wall. I also agree with some stationary drapery panels would help to soften the room.

We have a buffet on the other side of the room, but can’t move the table over more because it would block a door. Our layout is a little weird. I think I might move the guestbook and find a bigger piece of art. Maybe I’ll move it to the living room.

Curtains are also a great idea! I’ve never hung curtains. This is our first house and I didn’t really decorate the apartments we’ve lived in, so this is all so new to me.

Here's help for hanging curtains,

https://fredgonsowskigardenhome.com/2011/05/03/the-right-way-to-hang-curtains-and-drapes

Definitely a large horizontal mirror or piece of art -- a print or a painting.

Print taking up 2/3 size table width please and no personal wedding pictures or wedding anything. Too personal for public rooms I think and everyone of your friends who will be coming to dinner will have already seen it. Home Goods has great art posters as does World Plus Cost Market.

Here are some different dining room wall configurations for inspiration. Go for it!

Where would be a good place to hang the guestbook instead? Our bedroom?

Yeah, master bedroom sounds like a good place. I guess I just didn’t realize it wasn’t appropriate to hang above the table, but now I know! Slowly learning!

Here is a mock up for you to visualize some options. Large colorful art, open rectangular lighting fixture, window treatments and table scape items.

Just do art not a mirror on that wall. You need some bright blocks of color. Don’t hang too high either. Center of art should be about 60-63” above floor roughly eye level. Most hang items too high. Chandeliers should be about 30-33” above table top too for reference.

It is always fun doing your first home! No need to feel bad, we all learn from each other here. You will have a great time. Good you came here because we might be able to help you avoid mistakes. Enjoy!