Learn to block
Easier said than done for some people but when you find yourself in an dis-advantageous situation, you have to learn to chill. Hitting buttons while in the negative/opponent has frame advantage will get you killed. This comes with learning the game and it’s situations. Like in Tekken it helps to know the strings or be able to make an educated guess based on risk vs reward. In Street Fighter, you need to be careful about crossovers and overheads. Once you learn to block you make the other person have to change up their game plan and not randomly getting hit will eliminate any free damage you are giving them. Being patient often pays off. Eventually in time you will realize when they have over extended themselves an you can stick out a normal and start your own pressure.
Learn a “safe” mid screen combo
This is like a string in Tekken or cr.mk xx fireball in Street Fighter. You want something pretty safe so they can’t punish you too hard but you can get some decent damage on them from it. If you watch your game and character of choice in some matches online you will notice they will use a safe type mid screen combo pretty often.
Learn an easy punish combo
Extremely important no matter what game. When your opponent messes up, you need to punish them hard. For example Ryu wakes up with Shoryuken and you block it, you need to punish him extremely hard at this point. St.hp xx super etc. In Tekken, maybe they whiff move in your face or you block a hop kick.