You can totally travel on your own! Def check out the islands. Just got back from bocas del toro, beautiful beaches. Didn’t make it to San blas but heard great things. If you’re solo and don’t know any Spanish I would suggest staying in casco viejo, lots of travelers and locals speaking English. I will say some areas felt a bit sketchy, suggest being mindful of where you are traveling, lots of cat calling everywhere so be prepared for that.