hey im entering my 4th month of guitaring soon and im progressing well!
my technique is to pick 5-15 songs which include techniques that i find difficult
and throughout that month i practice those songs.

well im pritty stumped for songs that are 'challenging'
to an extent!
im currently just finishing learning
Avenged Sevenfold - Scream
Dope - Nothing For Me Here
The Strokes - juicebox
Weezer - My Name Is Jonas
One - First Solo

all songs had parts that i struggled with, and now im great at!

so do you have any more 'intermediate' song for me to try out?

try no future by Anti-Flag, although you might not like the song...
Surf Wax America is a good one aswell, but i think the intro is higher than intermediate really
Purple Haze...
No endeavour rivals science in its incremental progress towards a more complete understanding of the observable universe.
the chromatic lines in "ashes in your mouth" by megadeth are great for not only building chops but for string skipping too. as well as the solo to "sweating bullets"
A good ol' classic for fingerpicking, would be Stairway To Heaven. And "Hey There Delilah"!!! by Plain White T's (Pretend I didn't say that last one!!).
so far ive added, sweating bullets and surf wax america ; im still looking up ashes in your mouth and no future.