How much data to get for an iphone?

So i'm planning on getting an iphone. I have no internet at home.
i will use the phone for snapchat, kik, and instagram (mostly snapchat) the most. I will get games that don't use internet and stuff like that. And for music, i can download it off my laptop whih doesn't use internet lol.
I know downloading apps will use a lot of data but oncei get the apps i want i'll be fine.

How much data will last me if i use snapchat a lot? L i can get on facebook on my moms phone and i can use her phone for like other stuff (she has unlmited data.

Do you think 3gb of data will last me 90 days?
I will have unlimited texting and calling

I have about 2 gb per month but i don't use it all. I use the same apps and all you have to really be careful of is streaming live videos (like youtube) because it uses a lot of data. Also, try to limit the use of snapchat without Wi-Fi, but not to an extreme

Anything that has a lot of animation, video, or pictures to download will use a lot of data.

Most people get by on 2 gb per month if they have Wi-Fi at home. Your use will use a lot of data. At least 4 gb. However, verizon, and maybe other carriers will notify you if you are going over and you can add data. If your carrier does that, then start low and add as needed. That way you don't pay for more than you need.

Anything streaming uses a alot, video or audio. Texting stuff doesn't matter at all. You can also monitor it the first month or two and get an idea how much you are using.

That depends on how much you are out of your house, how much video watching you do, and if you connect your phone to Wi-Fi or not. Safe bet would be 2gb