I would make it clear you need someone to design this for you. If you want someone to print for you, expect to pay. Be clear about timelines too.
Does your school have an engineering or design department? That would be a possible route to get designs printed. If this is for a project with a deadline, you could coordinate with one of those departments and maybe arrange a joint project. They do the design parts and you handle logistics and concepts.
I'd be interested in fiddling with this but don't want to commit to anything. I'm a hobbiest and could use the CAD practice.
I got into 3D printing this year also. I wanted it to feed into my other hobbies and general tinkering. Aside from getting the printer to run well, it's really satisfying to design something functional. I was so proud when I replaced my broken washer knob with 10 min of CAD.