Go mid, harass enemy champions as much as you can and if you meet with more ranged then melee get the morello and hextech so that you can spam your ability's if they are more stronger melee like xin or trynd use the hourglass so that you can use it's unique active when you are in deep trouble and IF you die you might have an guardian angel on you and you wont die you'll just wake up and then you rift away if they attemt to follow you, use hextech on either the closest or the fastest because if one champion hits you, you are dead after guardian angel you can only afford 2 rifts in a row and you dont got any hp to get into a fight now so rift away and hide and return to base for hp regen and mana regen and stronger items.
Try to get the blue buff after level 6 so you can spam your ultimate rift walk and all other ability he got use all abilitys you have on the golem you'll get all the mana back in no time.
When you've defeated the golem you should have the blue buff. Now you should be free to kill almost anyone in the enemy team you can look for an good opportunity and strike fast be sure that you got force pulse ready so they don't get the chance to run.