Hello,
Yes you should finish GF2.
You have what you need to play, you may not be able to get the exact tone, but that is less important than learning songs.
As to what song(s) you should learn, I would have a difficult time learning a song I didn't like. So maybe start by looking through the songs list for a band you enjoy and look for easier songs to play, these will show as a number of picks. 2 picks will be easier than 4 picks and so on.
Alternatively you could look for songs "made easy".
Humbuckers are a type of pickup usually associated with hard rock sound. Think AC DC, Kiss, GNR etc. Your guitar will have humbucker pickups.
But what you have is absolutely fine to learn how to play and learn songs. The Mustang line is a decent line, maybe checkout YouTube on how to use the controls to dial in your tone.
Forgot this one, the more time you spend on lessons and your gear the more you will learn.
edited
This year the diet is definitely gonna stick!
