press 236d. if you don't have stock you will start charging instead. that's good. repeat until until 236d comes out.
now, you've gotten in and the goal is just to mix up with 6a/6b.
get charge in neutral. hit them when they come to hit you. 5b/236x/3c/jB/jC are the best tools for hitting them when they want to hit you. use j236a to restrict their movement.
It's hard to identify a character with worse normals than Tsubaki, so really what I gave you is just roughly the gameplan against Hakumen, Jin, and Ragna.
You have worse normals than Nu, Mu, and Bullet too, but the gameplan is going to be different. Of course you want to be in against Nu and Mu, but since you've got worse normals, you can't just try to rush in or you'll get killed.
Bullet is a similar story. You want to use your mobility to your advantage, until you can get in. But her pokes, jabs, and antiairs are superior. It plays somewhat similarly to the zoner characters because if you let her get heat 2 life is going to be really hard.
every char has lots of minor adjustments that need to be made on top of general gameplan.