i will tell you this, because this happens to alot of beginners and they get out of nitro because of it.
1st be patient and take your time, check things out before you try and start it.
2nd make sure glow igniter is charged, starter box or rotor start batt is charged or whatever it is you will use to start it unless it is a pull cord.
3rd you may have to tune it EVERY time you run it, sometimes you dont have to touch the carb but be prepared.
4th if it does not start, make sure fuel is getting to the carb, glow plug is good, igniter is charged. when you try to start it and fuel is comeing out of the exhaust it is too rich etc....
5th and be patient!!!
these are just a few things that i have seen take people out of the hobby.