ancient oracle
I tried to get into 40k but got extremely overwhelmed with the amount of rules, characters, point systems and more. I didn't know where to start and when I first played a game, I was dragged into a 6+ hour coaching match which drained me of a lot of my interest.
I decided to maybe turn a new leaf, and try this version, but as before I don't know how to start at all.
frozen bluff
start with a couple test games of a couple units
like 750 poitns tops
preferably having someone help you with that
and usually you'll want to start with just warscroll battles
then add on more rules from there
like the allegiances, and then the rest of the rules from there
flat atlas
What I did was just start with small games like @frozen bluff said. 500 points just rolling dice and getting back into the feel of the tabletop game. After that just slowly add more rules and interactions in. 500 point games don't take too long.
fringe marlin
I tried to get into 40k but got extremely overwhelmed with the amount of rules, ...
Don't worry about knowing all the rules. The rulebook is there as a reference. You're not expected to know how every single interaction works. Play a few small games with an opponent that is also learning and slowly increase the amount of complexity as it becomes more natural. Maybe dont even worry about missions or primary or secondaries until your 4 or 5 games in.
flat atlas
And when you're comfortable with your ARMY rules that's when you can get into the learning game
woven herald