montfj40- make sure you are setting the needles to factory settings when breaking in the engine. The documentation will tell you. If the manual says 2 full turns out on the HSN(high speed needle) then you close the needle all the way clockways, be careful not to over tighten, the needles are delicate. When the needle stops, back it back out 2 full turns, or whatever your manual says. This is the starting point for break in. Leave the LSN(low speed needle) at factory settings during break in.
Make sure that you have fresh fuel, and batteries in your glow ignitor. You can check your glow plug by pulling it from the head and sticking the ignitor on it, if it is not fouled up, and glows brightly, you are good. You will need to prime the engine, by that I mean you need to get fuel to the carb. Plug the stinger of your exhaust with your finger and give the pull start a few tugs, you should see fuel moving up the fuel line into the carb. Stop when you see fuel just enter the carb, you don't want to flood it. If the fuel is not moving to the carb, you can take the back pressure line from the pipe and blow into that a little to get fuel moving. When fuel is in the carb, hook the glow ignitor up to the glow plug, open the carb a little and give her a few tugs, it should fire up pretty easily.
IMPORTANT: Make sure you follow your instructions exactly for the break in procedure. This will maximize your enjoyment and the life of your engine. The temptation is to start letting it rip right away. I would search this forum for break in tips and the like, you are bound to find a lot of reading material.
Lastly, how long do glow plugs last? Who knows, I have had some that fouled up right away in a few tanks and some that have lasted the life of the engine. They tend to get fouled up more during break in due to the high amount of fuel going into the engine.
Hope this helps, don' hesitate to ask questions, someone around here will know the answer.