In Houzz, under Stories, look at articles under Bathroom Design and Remodeling Guides. Compile an Ideabook of pictures of bathrooms you like. If you can't find a designer, I have had good luck in the past working with a salesperson at a tile store - not a big box store, but a dedicated tile store. They are on top of the trends (if that matters to you), know what goes together, and can direct you to products at the right price point. Of course tile isn't 100% of what goes into a bathroom. You can always check in with the commenters here as you go along.

Choosing the contractor is very important. In our previous house we remodeled all the bathrooms and the MB was added in an addition. We used the contractor our next door neighbor had used for a similar project. But some peoples' personal recommendations aren't useful because they wouldn't know bad work if they saw it, and/or their project was so different from yours that their experience isn't relevant. So take personal recommendations with a grain of salt. Ask for references, contact them, and see if the homeowners will let you look at the contractor's work. Pictures on websites may or may not actually be their work. You may have to wait for a good contractor. We waited almost a year for ours to be available.

As kandrewspa suggested, I recommend you compile pictures of bathrooms that you like. You can even just save the image on your computer. Not only does this approach give you ideas, but if you consistently save the same sort of image (for example, very modern European looking bathrooms with a curbless shower), then you can trust that this is something that you really like. Once you have those pictures, ask yourself what exactly it is that you like about each picture--the color, the design, the windows, etc.

My other suggestion is to write down step by step what you expect to happen. Ie remove wall section to install new door, reconfigure plumbing for new door location. Oh that’s right, I have to select and order the new door… It’s a useful exercise to organize all your thoughts and create a task list. I do this for every job even though it might never be seen other than by myself.

You might consider a design/build firm. They are a one-stop shop for projects. I've used one personally and for clients for a number of years. They have on staff designers to help with layout and materials selection, as well as tradespeople (carpenters, electricians, plumbers, tile setters). They also have great connections with trade sources for fixtures, fittings, hardware, appliances, etc. And they take control of the whole project.

Above all, get recommendations from trusted friends, family and neighbors.

You really don't need to get a Ph.D in bathroom or kitchen renovation if you hire a good, competent, trusted GC.

such good advice already :)

we gutted and redid a bath during Covid (def don’t recommend that) things that we learned:

local tile shop was the best, I get overwhelmed with tile and they really narrowed things down for me - plus they knew my tiler so they worked through everything that needed to be ordered which was nice

Both our sink and tub were cracked when uncrated and then had to be re-ordered so additional delays (so wasteful) - the plumbing supplier had held the fixtures as they came in waiting on install, wish we had thought to check that things were in one piece upon arrival :/

we waited extra time for the best in town tiler and he was worth.the.wait.

try to have some fun and enjoy the process :)

Ask what the contractor uses for water proofing IMO only schluter . The actual design of the bathroom is decided by how easily any of the plumbing can be moved. Toilets are the big issue there. As for the stuff in the bthroom I like a vanity with all drawers and not tiny ones . I use Godmorgon from Ikea often but use my own counter and sink I like 12 x24 porcelain tile, plain usually, and use it for both bathroom floor and shower walls with the same tile only smaller for the shower floor. If you keep all the major things simple then wall color and accessories can be changed when the mood hits you . Bathroom reno are always time consuming so make sure you have another one to use. We actually had to use a neighbors in one case .

Thank you all for taking the time to respond, it really is appreciated. As we start this “adventure” I’m sure I’ll be posting more.

We are lucky in our house to have two other full baths.

Again, thank you all for the great advice.