First thing is to find out where the fuel leak is coming from. And get it taken care of. The select has it's engine preset from Hobbico, so there should be no fiddling with the adjustment screws to get it to start at least. But most likely you will need to adjust it a 1/2 turn or so afterwards.

As far as your glow plug starter goes. Make sure you fully charge it. The sub-c batteries they use in them are anywhere from 1400-2300 mha. So figuring a 110ma charger... 10 hours will not give you a full charge, which is what you need to have on a new battery anyways, but it's enough to get the plug hot enough.

But glow plug will draw about 3A for reference. Take the glow plug out, and connect the starter to it. If you get a nice red hot glow, the plug should be good, but it's always good to have a spare handy to swap out and double check.

I always plug the exhaust with a finger while spinning the prop to get the engine to prime (do not connect the glow plug starter just yet) on full throttle. You should get some spray back out the carb. But, be careful not to flood the engine which can hydro lock it. That can lead to a failed crank. Once you are sure the engine has fuel, attach the starter, open 1/4 turn on throttle, and hit it with the starter. It should fire up, or at least sound like it is firing. Worse comes to worse swap out glow plugs for another A3.

Your first priority is to find out where your getting fuel leaking from. It could be anything from a cracked fuel line, loose bolts, a bad gasket in the high speed needle, etc... Without this fixed anything above about starting is worthless.

What ever you do, don't rush things. This isn't a hobby where you can take too many shortcuts. Shortcuts lead to mistakes, which lead to cut fingers or crashes... and crashing sucks, so do chewed up fingers.

Good luck