Have you got a VR headset? If so, enabling VR should just be as simple as pressing the “VR Preview” button in the “Play” drop down menu in the editor.
Then you want to work out how you want to move around. The VR template is built for teleporting around a project with a floor as far as I know, so that might not be what you want anyway (still worth looking at it though). If you want to “fly” around you can make a Pawn and bind a key or stick to do something like “Add World Location” to your Pawn.
It also wouldn’t be that hard to merge your current project into the VR template project though. Just “Migrate” your level to the VR template project and all everything you need should come across.
Hope that helps point you in the right direction!