How to begin a modeling career at fourteen?

You are probably a little too short to find a lot of work. Even commercial modeling sort of implies that you're at least 5'6" but even then, you won't find a lot of work unless you're 5'9" or taller. Definitely forget about runway modeling. In other words, if you're trying to eventually make a long-term career out of modeling you should probably consider other options. Now, if you're just looking for extra money on the side or occasional jobs, that's different. You need to start building a portfolio. Since you'd probably get into commercial modeling, get very natural poses and head-shots taken. If you're very pretty, sometimes photographers will give you shots for your portfolio for free in exchange for letting them use your pictures on their website, etc. This is rare but sometimes possible - just ask - worse case scenario they will just say no. Once you've made a portfolio, you need to talk with a credible agency. They can refer you for jobs and help you understand your options. This service can be expensive, be warned. And there are many scam artists out there. I forgot to mention: if you don't live near/in a big city you can pretty much forget it too. You won't be booked if you aren't easily accessible. In summary: get a portfolio, find an agency, have a good head on your shoulders, don't be discouraged, and best of luck.