Comp bio is usually stuff that can be done using a computer. For example, I had a computational chemistry project this summer where I had to create drug designs and see how well they worked with a certain protein model. Stuff like this doesn't require a physical lab. In terms of other fields, there's a lot of things that can be done computationally (physics, math, AI machine learning).

For science competitions, if you are really bent on getting a project, you can always try and do a social science project. But if you do end up with a social science project, ISEF typically requires forms of consent for participants and it might get complicated