Krebs cycle help!!!

Please answer

bro it’s just oxaloacetate (4c) binds with acetyl group(2c) of acetyl coa to make citrate(6c) then citrate goes to a 5c intermediate then back to ocaloacwtate with all the atp and fad and nadh reactions. but i do cie so to check if u need to know just go on to save my exams go to revision notes for aqa, go to the page for respiration and you will see

It's OK I get it now.
But do you need to know the actual redox reactions too?
Newer question how many molecules of ATP produced from oxidative phosphorylation?
Some sources say 28 but where does the other 4 Atp go from the 32 Atp made in krebs cycle

isnt it a net gain of 28