Hi @rstrauss, welcome to the forum! Yes, there is a place where you can start a new web lab project, but it is a bit tricky to find.
If you are signed in and you go to this link: https://studio.code.org/projects, you can see where you can start a new sprite lab, artist, app lab or game lab project pretty easily (See below).
However, if you click on “View full list”, you will see that there are a number of different projects you can add. Scroll down to this section:
Then, click on Web Lab and you will start a fresh new project. To find it again, just visit the studio link above and it will show up in your list of projects.
Hope this helps, but if not, respond and let me know!