I was wondering whether do leg raises or situps train the oblique muscles, do they train them? If not, what can I do to target those muscles

They both do to some degree yes :) (when both sides of the obliques contract, they help with spinal flexion just like the abs!)
Otherwise you could add some side plank dips, hanging oblique raises, lying oblique raises, or perhaps russian twists!
One of them would be good enough - or you could work towards the clutch flag if you want to:
- that would also work them!
