Also wavedash. Oh wait...

Rip 9b

You could wavedash in 9b? Are you talking about the pseudo wavedashes?

Off wavedash topic on main topic question. How should one go about using their shield? I'm coming from fighting the cpu a ton where I hardly ever used my shield to online mode where I guess I should use it more. Is it about trying to learn the opponent before deciding when to shield or trying to read good attack options from the opponent from the characters relative positions then blocking if you see one? Is it a mix of these? Trying to use shield on reaction is hard/impossible (except against projectiles when used at long range) on online mode due to input delay. Up until now I've never seen people talking about how to properly use their shield....

You should shield AND spot dodge at the correct times (shield and spot dodge when someone starts to run towards you really fast, because they could either be going for dash attack or grab). It's all on your instinct

Normally, you want to always hold shield if someone's landing. That way, you can take an aerial and return with a grab, usmash, or aerial of your own.
Shielding aerials is a good idea in general. Another thing to do is to condition your opponent by approaching using shield during the first few stocks and then switching the way you approach.
Remember, if your opponent is directly in front of you and you're holding shiekd, shieldgrab. If they're behind you, shieldjumpcancel a usmash.

Also fireballs are good bait, as usually the enemy will do something predictable to avoid the fireballs

If for your character an up smash wouldn't connect would jumping out of shield and doing a back air do a similar thing? And how exactly does one do a shieldjumpcancel up smash?

EDIT: Nevermind, figured out how to do up smash out of shield.