I am just starting to use the CK and learning how to mod skyrim and I looking to find out if I will be getting in over my head.

What I plan to do is create a new group of magic called Shadow Magic with inspiration coming from the Erevis Cale series of forgotton realms books. My first step is to change spell effects to look more like shadows, so my question is how hard is it for a modding newbie to alter effects already ingame like changing the color of fire animations black and possibly slowing down the animation.

What programs would I need to accomplish this task that are free to use? would something like Blender be enough?

Is it also possible to add the new spell effects to the game without having to replace any current effects already ingame?

Any advice is apreciated, if things work out further down the road I would like to make a skill tree for shadow magic as well.

Also feel welcome to use this idea in your own modding, I have not seen anyone yet make any shadow like magic and would love to see an expert make some really cool spells.