Benching with the feet tucked back is the hardest to learn but the best technique for many.
Once you learn how, it’s easy to set up.
Looks like you are on the right track.
Make sure that the arch is coming from your upper back, don’t try to arch the lower back, it will do it on it’s own if you set up properly.
The feet will not touch the ground in a tucked back position, not should they.
Just apply pressure downwards at all time through the heel and you will be fine.
If your butt is coming up, try moving your feet wider a little at first, then once that feel ok, move them further back.
This may take a few weeks.
Stay with it.
Glad the feedback is helping.