For most people that's too close. Only exercise I can do comfortably after eating is rowing. For running, 3-4 hours is a time period that works for me, for a morning 5k I wouldn't be eating at all, just a cup of black Yorkshire Tea. Did my first evening 5k recently and didn't eat for 4 hours before.
You can run for 10-15 miles on empty, just a matter of building up to the distance patiently and not forcing it. And rest is every bit as important as the effort. Oh and a structured programme like c25k is better than winging it. I don't think high intensity intervals are what you should be looking at right now, just keep it steady, sensible and in a zone that doesn't feel shit and is actually enjoyable... you can do all that speed work later when you want to improve times, not now when you don't have the distance in your legs.
Gels are fine for supplying a little fuel mid-race in a convenient transportable pouch, but if you're going to consume something before just have real food (Medjool dates - nature's energy gels!). 15 minutes before though all I'd go near is a sip or two of water. Can't see any benefit to a gel pre-race, I'd have thought you'd start fuelling 10 miles+ in for longer races and a half shouldn't need fuelling it's already in the legs. Isn't it kinda like working against your body giving it a hit of gloop before you've even got going?