Go into training mode and use your normals and see what the ranges are both on standing and crouching opponents, since crouching opponents have an extended hitbox, so a lot of things that hit them, won’t hit a standing opponent.
This is so because crouch blocking is a very powerful defensive position and standing is by comparison very vulnerable, so having a smaller hitbox when walking towards someone has the advantage that you’re not so easily hit by pokes and can whiff punish.
Once you get a feeling for that just get into ranked matches and endless lobbies and try to apply what you’ve learned.
Don’t care about winning, care about learning.
If you feel the guy that has beaten you with his pokes, don’t just assume his pokes are better, go into training mode, setup a dummy with the character you lost to and see if his poke really beats your, or if you just got outplayed.
There’s no shortcut to shit like this anyways, you’re gonna learn in all departments of the game constantly and what people call footsies is such a large subject that you can’t just focus on that one part and hope to master it.
Read Maj’s Footsies Handbook and you’ll understand what I mean.
Like if you poke well, you’re gonna run into the problem that people focusattack your pokes, uppercut you, whiff punish or just jump at you while you’re preoccupied with the ground game etc. and each has its own solutions and new problems to it.
Just play the game, watch your losses and input stuff like the Footsies Handbook, UltraChen’s First Attack etc. bit by bit, in the meanwhile.
Fighting games take years to get good at, just try to learn and have fun on the way to getting good.