Sentence 1: I want to learn how to play guitar. 
 Sentence 3: I spent weeks and weeks practicing 
 Sentence 4:  I'm still not very good at playing 
 Sentence 5:  I think one day I'll be good at playing guitar 
 Option 1: I'm saving some money so I can buy a guitar one day. 
 Option 2: I bought my own guitar to learn how to play.