Is 2.5 gigabytes and 500 megabytes enough?

Well I'm a teenager so of course I'm going to use the phone a lot. I use the internet a lot and FaceTime a lot. I take pictures too. I'm also starting to like watching videos a lot. ( I can stop doing that though if it's going to take my megabytes away or whatever they're called )
My moms going to put me in the family plan with my dad and brother ( we switched to tmobile ). I'm trading in my aunts iPhone 4S for the new iphone 5c. I have unlimited call, texting, web but I have 500 mg and 2.5 gb. I don't know if that's good enough for me. I use the phone a lot and I don't want to overuse the new phone my moms getting me because I don't want her to pay a lot because I wasted all my mg.
I tried researching all this but everyone's saying different things. Please help me. Thank you! I'm not good at this.
Also, if I use wii, will it still take away my megabytes or gigabytes? Like if I'm at home using my phone with Wi-Fi will it take away mg or gb? Is cellular data the same as Wi-Fi?

No network data or when not connected to home wife is different. And it dose not use your data. What happens with a family plan is that minutes and data is divided among the members. I'm not sure how much face time uses. But social apps Facebook, Twitter use a lot of data which will use up data quick. The best way is connect to Wi-Fi when home and when outside use cellular data. And just watch what you use. 2.5 gigabytes is alot. But can go quickly if not paying attention to your use.