im pretty new to solidworks so i dont know where to place the model i downloaded so if i could get some help
It depends of your assembly structure. If you have a sub-assembly where the spring should be, than put it there. If you don't know from beginning how your structure will be, that's not a problem, you can start with one big assembly and after you figured out the appropriate structure, than can you reorganize with "drag and drop" (in the tree) the entire assembly. That's a very comfortable way to work if you are not sure how your structure will evolve, sometimes it's necessary to reorganize an assembly in two or more welded sub-assemblies and finally they will be screwed together.
I hope my answer match your question.