howdy there my dear fellow, i've struggled in the same vain as you have but i hope my pit falls can help you move past them, So firstly start by modding a game you like by that i mean try to make and import a mod into a game and get it to work, This lays down a slight foundation of import values and basic formatting. From these basics hunt around for some nice open game engines, Personally I'm doing my prototyping on engines like coppercube, neoaxis, these engines are free to dev and publish with and have the benefit of built in animating so you take the first steps into the building steps normally i try to keep a pipeline for my steps in a logical kinda line up (its the ocd....) find a art style][build the world][imagination inhabitants][design and model npcs and characters so placement and scaling reasons] . Now this short pipeline example is to basically say do NOT worry about anything regarding actions status values(to a degree!) etc etc, focus on the journey of building your game, your world, feeling out modeling first can give you the eyes to see where say a tree could be rigged to move or how to make a cluster object, all the skills needed start at the most honed you have, remember the greatest games are not what you can show someone its the story that that show is playing out.
now for a brief second i wish to say this does matter on the style of game you like as well RTS or isomets are good to start on neoaxis and its a good FPS base engine, coppercube has a more unreal fps devtool setup but both have wonderful world building tools.
feel free to contact me and pick my brain noodle i'd be happy to give any help i possibility can.
KEEP GOING YOU CAN DO IT! ^^