Question

2y+1<-3
2y +1<-3
2y+1-3
2y=-4
2y=-4
y=-2
Did I work this right

Answer 1

no,
you performed some "mathemagics" on this one.
in the third line your < suddenly disappeared, only to re-appear as an = sign in the next line.

correct method:
2y + 1 < -3
2y < -4 , I subtracted 3 from both sides
y < -2 , I divided both sides by +2

all done!