Modeling questions, is it hard to make it? any tips at all are appreciated?

im 18 and was thinking about submitting pictures to companies like elite, wilhelmina, ect. i know it's impossible to tell without a picture of me but i mean statistically is it hard? like for anyone in general or anyone you know who has tried to get called by an agency? i mean if i were to make it as a model, would i made some decent money at it? all of these are just hypothetical, lots of people have told me i should model and im going to a UC in august and could use the cash. it's also something i'd like to do. thanks.