Whoever you end up picking, go to the character threads for them and ask about what the most basic combos/setups/juggles are. That should give you a good place to start since it can be very daunting to find everything yourself. I can help with Vega or Cammy as an example.
(if you see an “x” after a move it means you do the next move quickly, so that you’re canceling it out of the previous move)
All characters: LP/LK (LP or LK) x MP/MK x HP x HP = your basic launcher combo, this juggles the opponent into the next character. You want to do only the first couple hits, and then react by continuing with the rest IF you see the first moves hit. Having the whole thing blocked will get you punished.
combo after juggle: crouch.MK crouch.MP x ScarletTerror (and you can Tag Cancel that to juggle to your other char)
important moves that link together: (a link means you don’t cancel them fast, you just do them after eachother)
cr.LP into cr.LP
cr.LP into cr.MP
cr.MK into cr.MP
standing.HP into cr.MP (HP must be close)
and you can cancel the end of those into ScarletTerror, RollingCrystalFlash, EX.Walldive/Izuna, Super, or the juggle combo
crossup attacks: jumping.HP (difficult spacing)
combo after juggle: stand.MP stand.HP x CannonSpike (and you can Tag Cancel that to juggle to your other char)
important moves that link together:
st.LP into st.LP/cr.LP/cr.LK/cr.MP
cr.LP into cr.LP/st.LP
st.HP into cr.MP (HP must be close)
and you can cancel the end of those into CannonSpike or SpiralArrow
crossup attack: jumping.LK (easy spacing)
Theres a lot more to both characters, but you want to most reliable basics down first!
Dont push buttons if you are too far away for the move to hit.
Be careful about acting after blocking light hits, since usually the person doing light attacks has the initiative to act first after a block.
You can Tag-in your second character doing any attack (so a risky Dragon Punch can be made safe this way, for a 1 meter cost)
Make your opponent guess whether your attack will cross up or not.
You can fake a jumping attack (jump in without attacking) and go straight into crouching.LK which can chain into a juggle combo.
Try doing one jumping attack or one point-blank light attack and then throw your opponent.