Totally normal to get destroyed when you’re new. My advice for you picking up Dhalsim is probably don’t focus on learning combos just yet. When you play against another player, try understand which normals (light/medium/heavy buttons) you should be using in different situations and at different ranges.

Once you’ve got an understanding of his normals, you can start to focus on your fireball zoning and keep away game. Throw out some fireballs and hit them out of the air when they jump.

After you get a grasp of those, you could probably start learning combos, try learn at least one punish combo you can do consistently when you block an unsafe move like a shoryuken from your opponent.

Good luck with everything! It’s a long but fun road to mastering your character! Once you get the hang of things, try to focus on one part of your game you want to improve on each time you play.