Why is my iPhone 5 running out of storage

My phone is constantly telling me my storage is full and I can't save certain things because it's too full. I have 400 pictures and I don't have a ton if apps. I have a white 16 GB iPhone 5. It's updated to iOS7. I had more space on my phone when I had 4,000 pictures. I can't figure out what is wrong. Do I have to buy the new storage plan? Or is there something else I can do? I need answers As soon as possible please!

IPhone 4s won't synch with Macbook pro?

My pictures that I took on my phone will be transferred to iPhoto on my computer, but the music won't transfer. I want to get my music that's on my computer onto my phone.

Added (1). It will say it's synching, then I'll get a message on my computer that says some things (then it lists a few apps) didn't transfer.

Someone who knows eBay

Say i want to sell an iphone for like 200. But i put it up at a lower price to attract attention. I expect to get 200 or more but if the bids don't get up to 200 is there a way i can only sell it if the bids get to a certain price? I don't do ebay if you can tell.

What does illegal start of token mean?

I'm trying to open this app on my IPhone and it keeps saying "illegal start of token >". I tried rebooting my phone and killing the app and it's still not working.

Could someone please tell me what it means and how to fix it?

What will happen if I put a sim card into my iphone 5 when I haven't had one this whole time?

I've had my phone for over a year now and have been using it without a sim card and it has been fine until now and my phone is saying "invalid sim" or "no sim" so I can't receive any messages or calls. At first when I would restart my phone it would be fine for a while then the error would come back but now it's like that even when I restart my phone. I'm planning on going to verizon tomorrow to get a sim card but what will happen to all of the data on my phone? Will it all be lost?

I tunes isn't registering that there's a sims card in my iphone 4?

Okay, a couple weeks ago i bought this fully functional I phone 4 from Amazon, a couple hours after i got it all set up, it said i needed to restore, so i went through the motions, but Itunes isn't recognizing my sims card. So I though ti'll just buy a new sims card and it'll fix it, but the problem is still persisting. What do I do?