To quote a recent figure...I feel your pain. You should probably begin by deciding what applications you want. Some applications, like web browsing, can be accomplished with relative ease (since it is already built in). Others, like syncing a variety of data with a pc, require jumping into something you might prefer to avoid.

If you will specify what functions you'd like to address, there are plenty on this forum that can tell you the knowledge level required to accomplish them. You can then decide if you want to take the leap.

As a minimum--at least in my opinion--you need a rudimentary knowledge of Linux to accomplish very much beyond programs that install themselves.
Tom