There are a couple things that help me stay motivated to work on a project (assuming it's in Minecraft. If not... sorry)

First, find a server with only a couple people on. That way the chat's not overwhelming, but you can ask for help or for people to come review your work if you want. I highly recommend a server called GreenLeafCreative. Really good community.

Second, have everything you need at your desk. if it's cold where you live, have a blanket on hand and maybe some hot cocoa, as well as some good old bottled water.

Third, listen to music you like or and audiobook. It helps pass the time and keep you moving while still having fun.

Fourth, it's a good idea to come prepared with some ideas on what you're going to build. Otherwise you'll find yourself flying around aimlessly with no clue what you're doing.

I hope this helped!

Best way to start a project.
is naming and dating your projects.
I always name my projects by the time or date I started the projects.
also name colony sites or countries.
I mean you build anywhere in your minecraft world.
build a project centre where you keep records of all your made projects you done.
because you will spend many weeks,months and hours and years on your minecraft world.
just keep that in mind.
think about a design whether it’s any sort of structure at all and build it.
takes a little bit of using your imagination with projects.
I build pyramids,towers and fortresses and etc.
and mix a bit of that with an underground base.
has my information been helpful? Please send me some feedback.
thanks.

Start small. Compliment yourself with every little thing you achieve and be proud of it. I feel like it's less with (world) projects, but with datapacks and programming in general, people often don't see the effort that went into making something that turns out shitty in the eyes of others.
By publishing small masterpieces on which you won't lose motivation and looking back on your achievements instead of forwards at the heap of work you still need to put in it, you can really get places that interest you. It doesn't matter that plenty of people walked down the same path before you, just do it because you want to have fun and not because you want to make something others will enjoy.