I'm a fellow Ryu main who's progressing through the lower ranks so I know what you're going through.
Here are some specific tips:
(1) Learn the range of your normal attacks. St.MP and St.MK are helpful to poke at opponents. St.MP is a combo starter so it's more useful yet has shorter range. Cr.MK is good for poking as well but right now St.LK has slightly more range and it's a faster move.
(2) Work on your execution by playing, playing, and playing some more. My execution has improved a lot just from playing the game and working on my inputs. Some time in training mode will do wonders. Practice and then turn on opponent AI or play Survival.
Also, there are some shortcuts that help with Shoryukens. I personally use forward->down forward->forward for Shoryukens when walking towards an opponent. When using cr.HP to combo into Shoryuken I use down-forward->forward->down-forward.
(3) Practice anti-airing! Anti-airing is a big part of the game. If you let opponents get easy jump-ins on you then you're doing it wrong! Start by practicing anti-airing with MP Shoryuken and St.HK.
But the best thing I can recommend are the Gief's Gym lessons that were put together by one of the r/Streetfighter mods. It teaches you all the basics and has helpful videos that demonstrate each lesson. Check out this link and try going through the first two sets of lessons (ignore the character links and try the general lessons).
https://www.reddit.com/r/StreetFighter/wiki/v/giefsgym/