Hey! I played DotA for 2-3 years exclusively before starting LoL... I found LoL a lot more enjoyable because it was more accessible to friends and beginners.
That eventually resulted in a vibrant community of friends to play with. Highly suggest it for this reason.
In terms of switching re: game play and mechanics--naturally there will be a lot of knowledge to gather. But mechanic-wise I'd say DotA is a lot more intensive. So the switch should be easy to make. League of Legends relies a bit more on strategy (the general approach to the game) and less on micro.