Lower body strength imbalance

I feel like my right leg is slightly stronger than my left leg during squats and leg press. Is this common or should I start adding single leg exercises to balance things out

Small strength differences are quite common

Try split squats with controlled movements

Bulgarian split squats are also worth learning

Dont overload your weaker leg suddenly

Check whether your squat technique is balanced

I noticed the same thing during lunges

Focus on controlled movement on both sides

if you notice pain or a major difference get it assessed