[xoannnnna]

Can someone please explain to me how to tell if two molecules are the same enantiomer or different enantiomers?

Here's the problems attached.

I honestly have no idea. Please help.

[xoannnnna]

By the way. Those are the right answers. I just see different patterns in each one.

In the first one, one is  R configuration and the other is S, but they're the same. For the 2nd to the last one, they are both R configuration but they are different enantiomers.

Am I missing something or doing this the wrong way?

[MissPhosgene]

Yes, I think you are doing this the wrong way. The first pair have the same R/S configuration (S), which is how they are the same. Two tetrahedral carbons with the same attachments arranged differently for tetrahedral center will not have the same R or S configuration ever.
 
A pair of enantiomers is defined as two molecules which are non-superimposable mirror images.
In order to see if a pair is the same or not, flip them around and try to fit one on top of the other. If you can, you have two of the same molecule. If you can't, they are enanatiomers.

I would make sure you are assigning R and S configurations properly.

http://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/sterism3.htm