Can someone explain the different endings cases and genders because I'm totally lost
You need a book and maybe a teacher really. I recommend Hurra Po Polsku 1 which covers 5 of the cases with exercises, rules and examples etc. This video may help you:
There are 3 genders.
There are 7 cases.
There are rules for declining nouns and adjectives based on gender and case, of course there are exceptions also which need to be learnt.
So for butelka there are 7 possible endings in singular and 7 possible endings in plural.
The video left out the case wołacz.
Gumishu has an explanation about cases here that I found interesting:https://polishforums.com/language/lubie-ten-kobieta-proper-grammar-56725/#msg1228188