The other thing you’ll have trouble getting used to if you play Magic or similar is that you do not play spells.
Your heroes cast spells. Which means you can’t play a spell without a hero in play to play it.
This threw me off for the longest time with starter spells (trying to Pillage without a hero, for example). When I’m using the play-by-forum spreadsheet resource, I now always write out “[Hero X] casts [spell y]” instead of “Play [spell y].” This forces me to double check that I actually have someone to cast the spell. For in-person games, I would recommend saying out loud who casts what spells.
Other tips for new players: download a searchable .pdf of the rulebook . It’s much easier to find what you’re looking for, even if it forces you to have a tablet/phone/laptop handy.
There’s a ton of useful stuff in the collected resources page, but particularly check out the Beginners’ Guides and New Player Reference Sheets under “Strategy Discussions”.
Lastly but not leastly, check out this thread on keeping track of stuff in Codex. Most important to me, personally, were tips to help me remember when I had or had not yet Teched in my 2 cards for the next turn, and which was my draw vs. discard pile.
Have fun!