It's not too late at all, your Step 1 is fine. Clinical grades could be better but nothing you can do at this point other than improve on your remaining rotations.
I think if you are interested, it would be worth shadowing as soon as possible. If it's something you still like after shadowing, then yes, I would work immediately to start with some research (introduce yourself to your home department if you have one)
You'll also want to work on away rotations soon as well. I believe there is a system called VSAS in place now so you'll want to talk with your home department, current students interested in derm, and your academic dean to see what the timing is for applying for visiting rotations through VSAS.
If you are a good taker and feel confident you'll improve on your Step 1 score, I would knock out Step 2 CS and CK as soon as you can. Your Step 1 score is good enough where if you don't feel confident, you can certainly delay it as long as your school will allow. There are more programs now requiring Step 2 CK before they'll review your application so you'll need to peruse the list of programs you plan to apply to, see if they require CK, and adjust accordingly.
Good luck!