it depends on what you want to do
if you dont mind last hitting minions in a lane alone then play mid ( it would suck at start but you will learn fastest about the game macro while playing mid, whereas playing top you will learn more about wave management , matchups , sidelaning and it can get pretty boring to a new guy as mostly its just 2 tanks tickling each other and trying to stop each other from last hitting minions).
adc / bot is in pretty terrible state at the moment and it sucks to play because you are thrown into a 2v2 lane and a single error can just put you too far behind in the game, you are very killable and your team will simply not cover you for you to deal any damage.
jungle is if you like the macro part of league, you learn about pathings, priorities, invading, timings, and plus point? you dont sit in a lane hitting minions 24/7. ganking is pretty fun , and you are a very high carry-potential with right champs like nidalee/viego/xinzhao for solo carry and sejuani/amumu for team gameplay.
Support is pretty fun when you start learning about vision control, roaming etc, It is easiest role to start playing, for eg- lux support is really good for new guys and its really fun and simple too. But downside is that you kinda dont get the kills (except pyke) so if kills trigger your dopamine you should try mid or jungle.