I don't really mind this early access, haven't even played some of the new heroes like Martyr yet.
As for tips apart from what Reg wrote.
Plague rider is extremely powerful and quite easy to play. His ult - think about Ryze's bouncy thing that deals a shitload of damage but remember it bounces randomly to the closest target so try to hit enemies when there are no creeps around. His third ability lets him gain mana from his own creeps and counts as deny so it's very very useful during laning. His second skill is a mid-late game buff that counters physical damage carries very well.
Torturer imo is not a good newby hero because he's very squishy, has very high mana cost on spells and needs a pretty good positioning.
Witch slayer - top pick from lowbies to high tier.
Arachna, being a carry, is pretty straightforward hero with a pretty good base damage and attack animation so you can use her to learn how to deny and last hit in practice.
Another pretty easy hero is Andromeda. Pure support, has a +%aura to allies, can save them with her ult or fuck up an important enemy hero with her swap. Just prepare to die a lot when playing her
Kraken - melee disabler, semicarry - his splash will help you last hit, he is quite tanky, especially after getting helm of the black legion which seems to be core on him nowadays. His ult can really fuck up someone in a tight spot, especially since it goes through shrunken head ( SH is a powerrful goto carry item that makes you immune to magic abilities and magic damage for a set amount of time )
Imo stay away from melee carries for now, they require shitton of farm which you won't get.
If you really want to try melee, get hammerstorm. His aoe stun is one of the best in the game, just remember to buy iron buckler so you don't get harassed to hell in lane.
Another thing is lane composition. Dual melee sidelane is a big no no unless you are playing against 5 year olds. Noticed that n Lol you can somehow survive such a lane. Here, with the denies and the higher damage from autos and abilities, you will be going back and forth to the fountain.
As for runes: those are double damage - blue, illusion - purple, haste - red and regen - green.
DD is I think easy to understand. Your autoattack do double damage
Illusion - spawns 2 illusions who take 300% more damage and deal 33% of your damage.
Haste - lets you move at top speed 522 for an amount of time
Regen - regens you to full hp/mp but if you get hit it cancels. You can also use abilities while regening and they won't cost anything that way.
Dunno if I will play tonight, sprained my ankle really bad during a match so I'm kinda not in the mood right now.