Hey there, kiddo- I am really sorry to hear what you are going through, as it is too common an occurrence. From what I understand, the split-up is amicable, so that is a good thing. I do not remember reading about any kids, and if that is indeed the case, that is a good thing as well.
I am not going to bore you with any philosophy lessons right now. You are going to hurt, and it is not going to go away overnight. Just remember that while you may be feeling devastating sorrow at the present time, that sorrow and hurt will only make you stronger and in fact wiser. Remember that each day you hurt is a day closer to healing.
Also, remember that you have all of us over here; so you have someone to talk to, even if it is just to vent.
Meeting someone new? Nothing wrong with that, so long as it is in a public place and there are no intentions for anything but the date, you should be fine. I have seen a lot of cheating, and experienced it over the years; trust me, you are not cheating. There have to be boundaries this early on, and those boundaries need to be respected (especially yours).
You are in a good position though, as at least your wife wants to stay friends. You can still love each other and care for each other even if you are not married; sounds like she is willing to be a girlfriend; Stay close, and maybe go out and do some shopping with her for clothes, make-up, whatever. I mean, you never know.
Nothing but positive thoughts for you, sweetie and stay safe :-)
M