Help New to the root way

[Brian_10_ga]

I have a note 4 verizon and I'm trying to do some pretty basic things. All I wanna do is change my dialpad style maybe even just a picture in the background or the layout of it all togather. Next how would I fix my text messaging background to say a picture or just anything with something not boring to it? If you can't specifically change the background per individual conversation, then say what about the general app where you can view all your messages? I know nothing of how to root what so ever. Sorry for the inconvenience and thabks in advance for thE help.