Wipe and restore the phone assuming the phone has activation lock disabled or it is enabled with your account.
https://www.icloud.com/activationlock/
You will only be able to restore your data if you have it backed up in iCloud or iTunes.
All the default apps will be there.
Use this link below for instructions how to wipe thee phone and put it in default mode.
If you can't update or restore your iPhone, iPad, or iPod touch - Apple Support
If you wanna add the phone back to your carrier or not just use WiFi and smile 🙂
Assuming you are on a GSM based carrier like AT&T or T-Mobile in the USA you can move the sim card to your old phone. (You may need to cut the sim card town to size if your flip phone uses a Mini or Micro Sim)
iPhone 1 - 3GS use Mini
iPhone 4 - 4s Use Micro
iPhone 5 & Newer use Nano
That list gets progressively smaller.
I would also go to settings > General > Cellular (or Mobile depending on version of English you use) and disable cellular data as your parents may have disabled your data plan and you don't wanna run up extra charges.