Need help with Lightroom classic?

I recently started working in Lightroom and imported a session, and ranked it using 1-5 stars. Later on, I imported another session and gave it a star rating but in my 5 star folder, I’m seeing both my previous session images as well as new session photos. How do I organise things in LR so I only see current session (ranked) photos?

Secondly, what’s the best way to cull images in Lightroom?