Kayla Harrison's opening up on all things UFC ... from her practice runs making 135 lbs. in the lead-up to her huge scrap with Holly Holm to whether she still has an interest in meeting Amanda Nunes in an Octagon!
33-year-old Harrison chopped it up with TMZ Sports ... weeks after she rocked the MMA world, moving from PFL to Dana White's promotion.
The 2x Olympic gold medalist and 2x PFL champion will fight 42-year-old Holm on the stacked UFC 300 card on April 13.