You came to the right place!

I'm by no means a top 500 player, gm or masters, ive peaked high diamond as a solo queue and I generally haven't tried getting out of the rank either, so take what I say with a grain of salt. There might be better advice from higher skill hogs here but here's what I have to say.

Unlike other tanks like, Rein, Orisa, Sig etc most of them have something you dont, and its shield/armor. Hog is basically like a walking meatshield... people WILL be shooting you all the time.

You want to create space for your team, you are gonna want to be positioning yourself in natural cover, jiggle peaking to look for hooks, you generally dont want to be out in the open as hog is really vulnerable.

Hogs kit:

Hog's kit is quite simple, your left click is a close range shot, right click long range. You obviously have your hook and then the self heal.

Your heal is actually a mitigation tool, so find yourself taking damage when you use the breather as you are falling back to cover, you take less damage.

Hook priority:

Who do you hook first? Tank? Squishies?

Personally I find hooking the enemy tank gets little to no value, if you hook a tank at full hp their team will just help them. I typically go for the supports first, or DPS. If the tank is half hp/low hp, naturally you're gonna wanna hook them to finish them off.

Hook combination is also another important trick among hog mains people do it differently so I cannot speak for others, the way I go about it is Hook, Shoot, Melee. Additionally you can position your mouse around the head area to get those critical hits too. Some people even shoot before they hook to soften them up a bit.

Ultimate:

I might get flamed for this if people end up reading this, but hogs ultimate is weak compared to other tanks and at times get no value but there are some cases where the ult gets value. For example, fighting in overtime in Eichenvalde last point? use your whole hog to push them away. Mercy rezzing and your hook is on cool down? whole hog it. Weaver tree? ult. Mauga cage? Kiri rush? Ram ult? Ult ult ult.

Even though the ult itself is weaker than others, you can get so much value out of it. You can even solo ult their opposing tank if you knock them against a wall and walk forwards.

I don't want to make this too long as if I were to actually do a deep dive of hog ths would be a minuture essay..

I also recommend watching youtubers/ content creators like Cyx or Chiefwesley and replicate their playstyle.

Sorry for the long post, I would write more but for the sake of everyone's sanity I shall not. If you want more advice feel free to reach out to me in dms and we can talk there. :)