Couple question(s)

Heya, new player here, posted here before and was met with many solid helpful hints so I ask again.

1. Been having a blast with this game so far but I seem to struggle with how to even begin managing to get out of corner pressure with seemingly no gaps to work with ? idk if I am just freaking out and going into panic mode and missing the windows or what, but what are some tips to work on this ?
2. I've been having a lot of fun playing as Belial (hes the first character i ever loaded with the game and who i keep going back to) I like his move set and design, but i've been playing with a few people who offered help through reddit and after a few games I get mad shade thrown my way "dont play top tier characters you wont learn anything" / "if your just following x you'll never improve" because im playing Belial, what makes him so hated? and I am starting to feel bad playing him so who would be a good recommended switch to, that wont be met with an insane amount of berating, character who is "noob" friendly. this is my first fighting game still learning literally all of the basics and don't want to take a cheap way out.

open to any and all advice, many thank yous in advance.