for those who's new to MOBAs, I figured I would make some pointers and tips to help a little.
1: movement techniques like slide, dash jump and dash slide are very useful and provides a lot of benefits, such as unlimited ammo during slide or giving you a greater speed and distance for escaping. but since the timing can be different for every heros, you might want to test things out and practice a little in the sandbox mode first.
2: last hitting (landing the final blow/shot on enemy creeps and hitting the souls that came out) and denying (hitting the souls from the creeps that the other team kills) are of the utmost importance in the early laning phase. during those times, try to focus on staying alive and getting souls through last hitting and denying. if you have difficulty doing that, you can always try to focus on just one of those. even just simply denying the enemy of their souls can make a big impact in your game. and remember, using melee attack to last hit creeps will give you the full amount of souls in one go, instead of having some flow out afterwards.
3: while we're on the subject of melee last hitting, if the enemy player in your lane is last hitting and denying a lot better than you, consider to just focus on lowering the ho of their creeps but don't kill them yet. once they're pushing close to your tower (Guardian or Walker), go in for the melee to get full amount of souls from that. of course, make sure the enemy isn't at a position to punish you for it. because you you can melee the creeps to last hit at the top of the stairs and they might still be able to hit you with some decent damage. so try to keep some cover between you and them while doing that if possible.
4: your towers are not as powerful as you think and the creeps are more powerful than you think. Guardians and Walkers target the closest enemy and focus on it first. so if an enemy wants to dive at you, even if you're right next to the tower, they can avoid taking damage if one their creeps are closer to the tower than they are. and in early game, the creeps do more damage to you than you imagine sometimes, so if you don't have any creeps with you and you want to dive an enemy behind their creep wave, you will take a big chunk of damage from the creeps or maybe even die to them.
5: spend your souls. I know sometimes it is tempting to save your souls for some big ticket items, but in early game that can be suicide unless you're really good at avoiding damage. just a few of the 500 souls tier items in your inventory can make a huge difference in your damage and your survival.
6: map/UI awareness is very important. try to take a look at the mini map and the top of your hub from time to time to see where everyone from the other team is. even in early game during laneing phase this is important because people from near by team could be coming in for a gank, so you want to be aware of the situation at all times. especially in later stage of the game, if you're pushing a lane and you see none of the other enemies on the map, then you might want to reconsider before keep on pushing. and if your team had been pushing but you see your team's HP are all low and their ults are all on cool down while the other team still have full health, then you might want to think twice before fully committing into that next team fight.
7: try to know the map well and know all the nooks and crannies, shortcuts and those void veils (the shadowy gates that's like a one way mirror). they can really come in handy when you are getting chase by multiple enemies. this being a 3rd person game, people can sometimes round the corner and miss you if you're hiding right at some cover at that corner or going to another path that doubles back towards their direction. just don't count on it unless it's some "you're already dead so might as well try it" situation.
8: the map also has a lot of vertical locations, try to use them to your advantage. for example as Dynamo or Haze, you can help your team by jumping off the roof at the right time to ult the other team for great effect.
9: try to take as much farm safely as you can. lanes are pushed out but it's not safe to keep going? pull back and farm the jungle creeps (the stationary ones). enemy is pressuring your Walker or the front of you base? make sure to deny as much souls they produced as possible. always break all the crates and gold statues. you can find souls, buffs in them and it's almost always worth it to break them and check. of course don't do that if you're rushing to help out your team or defend base thou.
10: this being a shooter, there IS damage fall off with your weapon. try to find a good distance where you are able to take enemy's shoots without actually taking too much damage in order to secure last hits and returning some damage either with your weapon or skills.
that's about all I can think of at the moment, but I'll put this into the OP and add more if I can think of them.
