I've played a couple of games, you can play competently enough by just knowing the basics, building the recommended items, doing your best not to die and not playing "weird" champions. I've been trying Clinkz, he's really easy to play, I never lost with him, always end up with ridiculous scores like 20/5/25 and 250 minion kills, just push your lane and immediately gank other lanes or chunk exposed towers, and escape with E. Later in the game, stay behind the meat shields, open Q and annihilate people. Of course I'm still a giant noob, but so are other people, since the game has adaptive matchmaking and such. If you give the game some time, try different champions without ever overexposing and read up on a few tips you'll get the hang of it.
As a LoL player who has never played the original Dota, I realize that laning is harder and it's generally hard for me to adapt to it to a "good" degree, since every disable and steroid lasts soooo long in this game (I'd say 3 times longer than they usually do in LoL), and ultimates are much more powerful. It's like the Brood War school of balancing, "everything's OP as shit, gl hf".