I have been learning the guitar for a couple of weeks. I am slowing down in terms of progress. I have got into the habit of learning songs that I want to play and avoiding things that are probably very important like learning chords not in the songs and pentatonic scales/theory etc.

Any tips for keeping things fresh?
I would say that you answered your question yourself when you mentioned that you should practice things that are "probably very important". I guess I'd have to ask what you want to get out of playing the guitar. Do you want to have fun or become a technically proficient guitar player?

If you just want to have fun, Well, people at every skill level of guitar playing hit a wall every now and then. It can last months, but it will pass, so I wouldn't worry about it. Things that I find useful: Switching between guitars (particularly effective if you play both acoustic and electric), trying a new technique, and trying new music. I find it especially effective to listen to music that inspires me to play.

If you want to be a technically proficient player, then practice wont always be so fun and you'll just practice scales, chords, and arpeggios eight hours a day. Realistically, everybody finds a balance between these two somewhat opposing goals.
You're not slowing down your skills, on the contrary, you are doing the right way learning songs. All the rest will come along the way ^_^ Good luck!
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