Have fun this summer, but remember to keep drawing, whether it’s still lifes of pinecones or sketches of kids in a lake; take it from me, being rusty sucks if you want to get back to designing.
And if I could just add a bit to the good advice above, learning to rewrite your brief is a skill you’ll use in your career, so you might as well start now. Sometimes you need to reign someone in when they ask for something like the bike project and sometimes you need to fill in the details when they just want something “nice” (though the bike project needs filling in too). So if you get an assignment like the bike one, acknowledge that most of those things are nice to have but find a focus. Go to bike stores, watch bikers, talk to bikers, and figure out for yourself which of them is most lacking and focus on that. Throughout the process you can review the original list to see if improvements to those aspects can be made, but keep your focus.
Something else that has occurred to me which may be a good way for you to think about “innovation” is that innovation is more of an adjective than an aspect. It’s like saying make it good. You could have innovative style, durability, low cost manufacturing method, etc. which means you can ignore that requirement. If you do well with the other stuff there is a good chance it’ll be innovative enough.
And when it comes to sketching and creativity, sometimes you just gotta push through the crap. Don’t worry about making every sketch super innovative or unique or special, especially in the beginning. Just start making square bikes, round bikes, triangle bikes, silly bikes, tough bikes, whatever. Make a middle ages bike or a communist bike, just keep sketching. Evaluate the sketches against your brief later. You’ll come to a few spots where you think you’ve thought of every variation possible, then realize, for example, that while you’ve changed up the frame every single sketch has the same handlebars. And when you start varying the handlebars you think of new frames somehow. Usually you have to clear out all the obvious ideas in your head by putting them on paper before the great ones come.
Anyway, good luck to you.