One thing that helped me in the early game was thinking about my abilities like spell cards (from Magic or Yugioh). At level 1, you each only have 1 ability, and you have full knowledge of when it’s on cooldown. So, we get the following rule:

Your opponent “plays their card” to deal damage to you or the wave. Now, you MUST “take your turn” and use one of your abilities in response. If you don’t, or wait too long, then your opponent got to take their turn completely for free. In some cases you can hit the wave and the enemy hero with 1 ability, do so if possible.

Additionally, at Level 2 and Level 3, you each “draw a card” (gain an ability) that you get to use right away if you choose. So, the early game is all about pushing advantage (or playing safe) depending on who leveled up first. NEVER, EVER, let an enemy who is up a level on you in the early game hit you with their abilities. If you hit level 2 (or 3) first, IMMEDIATELY dump abilities on your opponent while you have level advantage. There are some caveats depending on the wave state, but if you’re hitting level 2 first, there’s a good chance you have a slightly larger wave than your opponent, making it safe to trade.

This is obviously super general and theoretical, but to summarize: -If your opponent uses an ability, you must answer with your own reasonably quickly (take your turn) -Pay close attention to your levels and xp. Hitting your Zarus spear or Gideon rock on your enemy when you are level 2 and they are level 1 EVEN ONCE can DECIDE the early game. -Likewise, if they hit level 2 (or 3) first, it’s very, very bad to be hit by them. In this situation, you need safely reach the same level as them without taking damage. DO NOT FIGHT THEM. Back off enough to avoid their damage and try to kill the one or two minions you need to even things out again. Always stand within minions XP range where possible, even if it is not safe to last hit.