What level do you want to attain in each language? How do you keep up that level while learning more and more?
I think languages are a super valuable thing to learn but as someone who is (only) bilingual I know how hard it is to try to maintain my second language effectively.
For multiple languages, unless I was using all of the languages every day in a work capacity or something of similar magnitude I don't know how I'd find the time to maintain my skills. So I certainly would be interested to hear your plan for how (as a casual learner I assume?) you'll keep up with the languages you know while learning more.