Kiša pada....

Kiša, kiša, kiša..
kiša sve cijeli tjedan....kada će prestati kiša....?!!!
Sada (ja)* želim zima zimu i snijeg ::::))))

* ja - it can go with or without "ja" --> "želim" is enough

Kiša sa pada....

Kiša, sa, kiša, sa, kiša... sa..
kiša cijeli sa sve tjedan....kada c će prestati kiša sa....?!!!
Sada ja z želim zimu (because it is acusative case. Who/what do you: like, love, wish, ... so it is always used for objects. I wish a winter - Želim zimu)   a i snijeg ::::))))

It is not necessary to wirte always the personal pronoun. 

Nice job. Keep it up. 

If you need any help, please, feel free to ask me.