You should
at least eat twice a day.
Its essentially what I do. Can't eat breakfast (it's either eat or make the bus and I'd rather get an education,) eat lunch, eat dinner, and then snack a whole lot. It'd be better if you could eat three meals a day but two is better than one and a couple of snacks.
I'm kind of fat imo, around 125 pounds for 14 year old, I don't want to pump in more stuff inside me
It depends on your height. If you're 5'10" or more then your pretty skinny, If you're 5'9" then you're pretty much average, at 4'11" then you're starting to get over weight.