If yes how exactly do you sell it and cash it in ? - is selling somewhat guaranteed (because of the popularity of the product or there's some slight chance that no one would want to buy it because atm is so big(not talking about current amount, but let's say higher - 30k/btc?)..Do you regulate the price once you can sell it, or the price is fixated ? do you use a specific bank desk for that or your bank (if the bank is working with bitcoin ofc)?
The easiest way is to use exchanges like Coinbase. They typically have buy and sell prices like normal currency exchanges and they'll buy whatever you're selling regardless of the current market price.
You could also set your own price by selling it to another person using platforms like localbitcoins.com
I don't understand your question about banks.
I looked up online on a lot of articles and the one thing i got is that Bitcoin is regulated regarding the market and the one thing that concerned me the most is that - say you buy bitcoin and then you cash it in (a.k.a you go out of the "bitcoin zone" or something like that) the bitcoin amount lowers? I mean in order for bitcoin to raise you need constant investments and no "cashing out" or using it to buy stuff like technology? If that's true doesn't bitcoin contradict it's own existence? If it's aim was to "change the monetary system" itself in any sort of way why is it lowering down exactly by doing so?(biggest i.e. was when bitcoin went above 12k/btc and on the next day/couple of days it went down by 20% because of people cashing it in.). And if that statement is completely wrong could you briefly explain me on how BTC is regulated and by what? After all that seems to be the most crucial part about it.
Bitcoin price isn't regulated by any entity. Its price is dictated almost entirely by the law of supply and demand, so if there's a lot of people who sold and few people are buying, the abundance in supply lowers its value.
Does it matter which wallet i choose for which country? I noticed there's a section about it with an option to choose which country is best for which wallet in the ofc BTC site, but for some reason it's not loading for me. If yes how do i decide that?
As far as wallets go, not really. I would advise you not to use any online wallets because they tend to be poor in security. If you're just starting out, you should probably try lightweight desktop wallets like Electrum (electrum.org). The best wallets are hardware wallets, and you have to buy them from their manufacturer. Google can explain this better than I can.
Exchanges are typically country specific though, so you may want to look up what exchange is best for your country. It's going to be hard using Bitcoins without at least one exchange account.
That's it for now. Sorry for the very stupid questions and thank you for the answers! Wish you all good fortune!
Everyone starts somewhere. Don't be afraid to ask questions!