Hello I am Nazrat. I've been Rank 3 with Ekko in EUW and 20th Worldwide,I had 70% winrate in 150+LP Masters and a lot of high LP players have said that my Ekko is very clean. If you'd like to watch me sometime or this guide was useful for you, you can follow me here :
https://www.twitch.tv/nazratlol
Okay , lets start the guide ;p

Ekko's playstyle is either agressive , looking to fight permanently or playing it slowly , rushing tower plates and then trying to carry 1v9.Both playstyles differ from game to game. The reason why that is happening is always because of the enemy mid/jg. Lets say if you cannot really push mid you are looking to just play it slowly and wait for the enemy to exit lane so you can get some tower plates. However if you can push you might be looking for some kind of rotation if it's needed , if not you can just secure plates. However lets say they have Nunu jungle you cannot really push all the time and stay close to the enemy tower without information on Nunu so sometimes you will be forced to go back and do something on the map. After laning phase you are pretty much permanently on side lane because you have great split pushing ability and you can easily get towers down / bring people to defend you and then look for plays on the map/get an objective. Being agressive with Ekko is very easy because the enemy team has hard time punishing your overagressiveness.
There are 2 reasons for that to happen:
1st - Your ultimate, your ultimate is broken , low cooldown , restores HP and gets you back to safe position most of the time.
2nd - Your passive, whenever you proc Ekko's passive you get an insane amount of movement speed for a couple of seconds which you can use to either chase down your enemy and ultimate to safety or you can just use it to escape.
Pro Tip: If the enemy is on top of you , chasing you and you see that you cannout outrun him , just proc your passive if you can and fly away.After securing Hextech Rocketbelt,Lich Bane and Rabadon you can easily E-Q-Protobelt-Electrocute Proc-Basic Attack-to-proc-passive to oneshot your enemy.

Ekko is INSANE! for SoloQ. His ability to be agressive and yet not being hardly punished makes him one of the best SoloQ choices out there. However if you are a new player and you want to learn the game as a whole I don't recommend you Ekko as you are going to stay alive in situations that otherwise you would die with other champions and that might create bad habits and make your playstyle worse.