Zone and play to normals is the safest point to start.
s.lk, s.lp xx lp bull head will punish A LOT of stuff early on. (Once you’ve played a bit more and learn where you can get bigger punishes, then you can start implementing them.) Also cancels into super for good damage, or you can sub the lp bull head for EX bull head and combo into V trigger linking Bullhorn after for good damage. It’s a really versatile low damage, 4f startup combo that i use a lot when i’m not sure of something. The two light normals give me plenty of time to hitconfirm and leave me positive on block AND put the opponent where i want them, so for a new birdie it’s really useful while you learn your range.
DON’T use too many banana/can setups at the beginning. EAT THE DONUTS INSTEAD. V-reversal is his best option if people get up in his grill, so building the meter is important. Also remember that EX bull horn has 1 hit of armour, and EX killing head is throw immune on startup.
c.lp and s.mk are your best pokes. s.hp is nice to throw out if you catch them trying to shimmy too much.
s.mp buffered into mp bull head is the whiff punish of great justice. Dont get predictable with it, but if you can sit just outside of your opponents poke range, 9 times out of 10 thats WITHIN your poke range, and if they throw out a normal, this bad boy will catch them and you can confirm a super off of it if you’ve got meter.
Start out playing SUPER simple. Birdie gets shitloads of mileage out of solid, basic play.