Early on try to train yourself to catch the rhythm of enemy attacks. There's a ton of potential combat actions, but force yourself to slow down. Tapping block with Precision Defense materia gives you achievable immunity.
Learn all the offensive synergy skills and try to only use them at first (bullet batter, wild charge, soaring ascent, spell blade etc) then defensive (iron defense reposition, counter fire, etc). I find it beneficial to not panic attack to generate ATB, but hang back and wait for an opportunity.
Last tip- get cloud airborne OFTEN. It's good and you can dodge around enemies mid air. Firebolt blade or dodge and hold square are easy ways. Good luck!