You assume this game must be rock-paper scissors. There's hundreds of different factos in play always, so dont think "i built damage, must mean that i can 1v1 anyone, no matter what"

In league, damage comes at a cost. Sounds like you're playing an AD carry. AD carries do facewrecking amounts of damage, but usually don't built defenses. carries need protection. They cant just go in and right click their way to a pentakill. They rely heavily on their team and how they position theirselves to be effective. Sounds like you went in 1v1. Sounds like you let this tank get in melee range and stay there for 8 seconds (which is very bad if youre ranged). At level 5, no offense, but you don't know what balance is yet. What may seem " omg imbalanced" now makes perfect sense once you learn about the game.

But some details might help me help you. What champ were you? what champ was he? What items did he have? (thornmail moght have done alot of damage to you if he had it) I can give you some tips for playing a carry next time. But the big one is: stick with the group and stay out of the way of damage. Some tanks (like Mundo) can hurt. For a defensive item, usually a Guardian Angel is the best choice. Stick it into your build when ever you are having trouble staying alive in big fights.

Oh and bots aren't meant to be ****. Beginner bots are meant to ease new players into the game and for testing out new champions and builds. Once you can beat bots reliably, then that's a good signal that you know the basic controls and mechanics. Intermediate bots are the same things, although i don't recommend playing against them too soon because they get to cheat alot :3