Earlygame
Levels 1-7
EARLYGAME PATHING - starting blue with your solo laner is currently meta on ob8, you will do blue buff > red buff > cyclops camp > and then go to one of the mid camps (buff/oracles) and then clear down your side of the jungle on duo side ending clear on back camps, and reset and head out to scorpion and backs and then you have free pathing to do as you wish.
Midgame
Levels 7-15
At this point in the game your hammer should be maxed, it is a very useful poke tool to use in combination with your tectonic rift. Your ability to play around your team and setup on thor is what makes him so powerful. Don't be afraid to sit on corners with your teammates and look for picks with cc chains. Your main way of killing people mid game will be using the "Ult combo". This combo is used when landing on an opponent without cc immunity.
To do this combo you will land your ultimate on them, auto attack, throw hammer, auto attack, tectonic rift, auto attack, beserker barrage. This combo will kill majority of carries in the midgame, and will leave tanks hurting.
Lategame
Levels 15-end of game
Lategame is when thor is at his scariest for enemy tanks, his wall ability is a very potent lategame ability for killing enemy tanks with your team. A ranged 1.4s stun will lead to most of them taking 70% of their health if used properly with your team. Don't panic ult early in fights, using your wall against diving tanks to peel your team or to turn on them is very powerful. Ulting is a hard thing to get a feel for, but if you are patient it usually benefits you.