A much cheaper alternative is courses through edX (I think it’s free, unless you want a certificate of completion in which case it’s 50 dollars):
My kids have taken edX courses and enjoyed them. They recommend paying for the certificate if you can, because it helps you stay on track, which is difficult to do with this style of teaching/learning (I mean the massive online courses).
I would also recommend reading over the summer. Depending on your areas of interest there are great books that you can find at the library or buy.
I don’t know much about in person opportunities. Is there a local historical society to you? You might try contacting them to inquire about projects they might be working on.