Learning laguages

Hey, my dream is to be a polyglot. My native language is Polish and my English is at (let’s say) B2 level. I would love to study some philology or linguistic, but I don’t really know which one. Truly, every language fascinates me and I would like to learn as many as I can. The thing is: should I study one particular language? Or maybe it’d be a good idea to study a major which offers two languages. There is Russian + Czech together and it would be great, because it would be two foreign languages. The problem is, I’ve never learnt any of them, and polyglots say that it is bad idea to study two foreign languages simultaneously at the same level.
My other option is it study a major which offers English + Arabic (or another second language), but will I focus enough at the second language, while I’ll spend a lot of time for studying English. (I think that I’m able improve my English on my own).

I hope that someone will recommend me something, because I have 4 months to decide, and I’d like to begin learning another language from now.
Greetings, Darek.

I don’t know which language to recommend, but all of those sound interesting. Arabic sounds easier to me, but if you already speak Polish, then Russian and Czech probably look a bit familiar already. (They are completely foreign to me, since I don’t know any Slavic languages.)

Czech and Russian seems to be awesome for me, but the question is whether I should learn 2 languages from zero in the same time? I think that I should focus on one, otherwise I won’t acquire them very well. I don’t know, maybe I’m wrong, but it is my thought. Always I could spend some time to learn basics of one of these languages before I start studying it. But I could spend only 3 months, entirely, for it. Would it be enough? Those languages are similar (both are Slavic as you noticed) and it could be mixing for me.
Sorry for mistakes, if you can see any. Correct me please if there is something conspicuous.

I’m not sure about an answer to that question, but maybe someone else here has some thoughts.

It is obviously an advantage that there are in the same language group, but it could be also disadvantage when I learn it in the same time ( a lot of similarities could mix ) I hope someone well-versed will answer.