Here's some pretty basic tips cause I don't play Vakiha cause not doing way too many Rebeats in a combo for her is impossible for me; I play Satsuki and Kouma cause I don't accidentally do stupid Rebeats with them like my random Nanaya j.C [j.A cause I'm stupid] 2C 5C [5B because I mash B before the jump] crap.
-Shield is NOT useless. It seems useless against computer because they attack really randomly. When a person gets in range for an attack they attack. Computers randomly wait half a second for no good reason sometimes. Learn to EX Shield some easy EX attacks like Mhisui j.214C and it'll help a little with timing for real shields.
-Blocking is learned by looking at the opponent and thinking. For the longest time I blocked low all the time and for some stupid reason STOPPED HOLDING DOWN WHEN THEY LANDED AND WENT IN FOR A SWEEP. Seriously my friend played Mhisui against me once when I was really bad and he did j.C which I missed blocking cause I was crouching, then he didn't connect it to anything and went in for a 2C to pick up a combo, and I stood up as soon as he landed, making the 2C hit.
-Flamepit setups are meant for you to use a blockstring in. Only use EX flame pit after you get them on the ground and they can't tech, and have a blockstring ready. Vakiha isn't too bad in the regard that mashing buttons can create pretty decent blockstrings, but at the same time you have to keep in mind that the moment you are too far for your next attack to hit them and keep them in forced block, they're gonna throw an attack back at you. Block it, counter it, shield it, whatever, the thing is you have to know what openings your opponent can possibly attack in, and get ready for a counterattack in those situations.
-Vakiha's flame tongues suck on the ground, Akiha's shouldn't be used on the ground either. Learn to TK them or don't use it.
-Don't be afraid to blow up a 22C flamepit a few seconds after you set it. It creates massive frame advantage if it hits or is blocked and just remember it's just a bit of meter. It's not hard to regain. I know it's always frustrating to burn 100% meter and only get chip out of it, but it's not a waste as long as you don't eat 4k damage back. Vakiha is all about not getting hit by forcing the opponent into not being able to do anything.
-Also try not to play against the computer. It's stupid and doesn't teach you anything. I can play Kouma completely wrong without using throws and do well, and play my fucking terrible Nanaya and get to round 73 in survival. The computer teaches you people don't block, and you'll get really frustrated when they do. It forces you to not learn any blockstrings and to not have any clue what to do when you're in a blockstring.
-There are no good simple Baras for Vakiha anyways, and it's one of the harder things to do in the game no matter what, so you shouldn't bother with it right now. I can't bara right now outside of practice and I don't mind it.
-Dash>Throw is fun. It's twice as fun when it's Dash>41236C for Vakiha or Dash>Kouma/Satsuki's EX throws. Lol I think Satsuki is even meant to do it cause 641236C is one of the only things that really cancel out of Satsuki's ground dash.
-Learn combos and blockstrings now. Learn to go into them from hitconfirm, and learn it well. I also don't play Vakiha because I can do her 623B loop easily enough in practice but can never get it off in a real battle. Also I am way too used to most bnbs and do launch>j.BC which ends the combo right there instead of doing anything that would be more damaging and gain me more meter. If you want top play Vakiha learn her combos well. You want to end the match fast with her because if you trade hitconfirms, you only get so many shots at combos since she has such bad defense.