Gosh I love Wittgenstein for this.

I highly recommend suffering through both early and late Wittgenstein (only wrote 2 books and essentially invented one of the 3 branches of philosophy).

Expect to only understand 10% of what he says, but that is normal.

Separately, pragmatism by William James is an easy 4 hour read and you can have 2/3 of the branches of meta philosophy.