Give it some time Mate.
I'd bet there are people installing and uninstalling mods to give you an answer.
In the mean time.
Some mods will over write a previous mod, so you get a warning.
That's normal.
Best I can say is,
Install 1 mod and do a test run.
Install the next mod and test run.
And on and on.
Some mods need to be installed BEFORE others.
It all confusses me and makes my head hurt!!
Welcome to the Jungle!!