you can, but you shouldnt because its a lot harder.
you have an easier time to focus on the games fundamentals, when you play a mechanically more accessable champion.
that being said, shaco isnt a particularly mechanical champion, and as far as i understand, the people who play him well just have played him a very long time and learned almost everything there is to learn about jungling, gank pathes, macro play etc.
so if its shaco you want, youre good. he might even be an ideal champion for the purpose of getting to understand the games fundamentals. he does have a steep learning curve though.
he might not be mechanically difficult, but relies very heavily on strategic planning and its going to take a very long time to learn how to play him really well.