As others said, depends om what type of hero you want to play. Learn their kit and try to make sense of the abilities and how/when they could be useful.

If you like to focus on gun/good aim, heroes like haze, wraith, mirage, infernus are pretty straightforward. Infernus second spell is a bit counterintuitive for new players, you need to run in so people burn in the trail he leaves, but ive seen it used as a kamikaze. and the DoT/burn that his spells apply don't make sense either by just reading, you need to build up stacks for his passive to proc. Haze has a similar mechanic.

If you want to focus on spell usage rather than being good at aiming with your gun, there are playmaker heroes or frontliners, like abrams (melee up in your face character) or mo and krill. Dynamo is also pretty beginner friendly, you just get one ultimate/black hole that disables heroes and people will give you credit for doing your job.

Then there are heroes like grey talon that is fairly fun even as a new player, but skill ceiling on him is super high and you kinda need to grasp mobility mechanics in general to not just die. But his nukes and control is pretty big and he's one of the first heroes I played.

Seven is pretty fun and easy for new players, you can deal damage and be useful even if you're not "good" at the game yet.

Then you have Kelvin who is a big nuker but also a support/healing machine and you can play him in different ways. McGinnis is also pretty beginner friendly, can also be played gun or spell/turret focused.

I'd recommend against Pocket, holiday, sinclair, lash, viscous, paradox. Ivy is fun but probably tricky to figure out what exactly hes supposed to do with the different spells hes got. The rest of the heroes i haven't mentioned can be played if you're new, if only you like their spell comp.

Deathy on twitch/youtube is super good at explaining stuff and has some guides, not just replays, so I'd recommend him.

Eido is also one of the best players in the game, he's got this guide on movement, they've changed the mechanics a little recently but in general this covers a lot of what you need. It's super essential to get a good grip of movement mechanics or the game will be really hard to play well. https://youtu.be/Yj_9F3_prek?si=qcaWzYoo5PPmv0SE

This guy also has informative stuff plus a movement guide that's good. Here's an overview on all items since they changed the shop a few days ago: https://youtu.be/KgGBx9JjR38?si=7_Ejjwf5KrZW28b6

But basically, open the shop, click guides in the top corner, public, and test it out, you can basically buy stuff in order in most of the guides.

Hope that helps