If you can learn how to jungle you can learn how to lane. Look up streamers like Irelia Carries U, SoloRenektonOnly, SickMotion, BoxerPete etc and they explain how to lane.
But basically, you roam when it won't cause you to miss many creeps, in other words after pushing waves into tower, or when the enemy creep wave is slightly bigger than your creeps, which will make only a few of THEIR creeps die and mostly remain alive when you come back. You back in the same situations. If the enemy tries to fight in your creep wave, you almost always want to fight back. You should also learn how to freeze waves -- this is when like I said earlier the enemy creep wave is slightly bigger than yours, making them kill your creeps faster than your creeps can kill theirs. If you freeze the wave and you're ahead, you can zone enemies from getting even a single CS.
Keep in mind most of this is for top lane