Life is a time for education and 'other things' (np jakie?) . Everybody 'who' (niepotr) in THEIR 20s 'years old' (niepotr) (mozna tez inaczej..'everyone who is 20) gains different experience, they want to succeed and discover the world.
I haven't written 'some' ANY short poems. I haven't been to London yet, but I have been TO other cities. I haven't been a teacher yet, but I have had practice and I have worked at A summer play centre.
I haven't bought a car for myself yet, but I think that I don't need a car RIGHT now. I haven't been on tours around the world (przecinek) but WHEN I have more time I can do it. I haven't applied for a job yet (przecinek) but when I finish my studies, I will do 'it' (lepiej THAT) . I know that I have not done many 'thinks' (ortog, tu ma byc thinGs) in my life yet (przecinek) but I'm young and everything is ahead of me.