Okay, well down in the bottom left of the launcher there is the bit with the profile selections. That might include Forge and whatnot. From memory there are three buttons in the bottom corner and one is labelled 'New Profile'. Click that and it'll take you to a page of options. On there you can name it and select which version you want. Afterwards you can switch between your versions also in that bottom corner.
I hope this as helpful. If it wasn't I can just link you a video.
