Among your options – a summer exploration program, an adult or art center course, or a regular high school course – I think the latter gives you the best chance of producing portfolio level work. A combination of two or three would be even better. Honestly, I don’t know that you’ll be able to pull together a strong portfolio in the time available under any circumstances, but you will benefit from the training.
Don’t switch out of Spanish unless you are confident that you will be able to place out or test out of your prospective colleges language requirements. Do some research on this before you make this decision. Do you have a counselor who can help you?
In order to put together a list of matches and safeties, we would need to know your scores, rank and your financial situation. For example Kenyon does offer merit aid; Williams does not. I don’t know the acceptance rate at Cal Poly architecture, but I would doubt that you could consider it a safety. Remember too, a safety has to be one that you actually want to go to (and can afford) so if you don’t want big, you may have to look outside of the state system.
We are a dog loving family too but having a dog on campus isn’t a good idea. Many professors “share” access to their animals, though.