^for one, the French is about the fight for the d4 square. In the Pirc, you play for f5 and attack on the kingside.
I am garbage and can't improve

^for one, the French is about the fight for the d4 square. In the Pirc, you play for f5 and attack on the kingside.
You do not play for f5 in the Pirc. You are thinking of the King's Indian Defense:

You're not the only one who's garbage. Magnus is off his high in 2014 and for 8 years cannot improve. Give yourself 8 years!

The secret to getting better is getting your brain to do something that's really (really) hard for it.
Watching videos is ok for the awareness. But once you start the puzzling, you're taking the plunge.

#1
"I have a rating of about 500 and my highest rating was 599."
++ A rating of 500 is a sign of frequent blunders.
Always check your intended move is no blunder before you play it.
Hang no pieces, hang no pawns and you are 1500 overnight.
Hang no pieces, hang no pawns and you become 1500???
I am 1300 and you have to find forks and pins (most important tactics) to progress from 1200 to even 1300
pins and forks are included in hanging pieces. hanging a fork of a king and queen is still considered hanging your queen.
Pirc defence. I find the ideas are similar to the French. I do still think that your opening video is worth watching.
Don't focus on openings if you're 500!!! The French and Pirc defense have nowhere near the same ideas!