Mobile phone help

I'm on a sim only contract for minutes and texts only. I recently bought myself a phone which has internet, I'm just wondering can I use the internet on my phone with my own wifi, without having internet in contract and will it charge me ?

Yes, just go to wifi settings and connect .
Make sure you turn off data connection to network (O2 vod etc) and roaming (you want don't roam).

It's the same if your out, let's say your in Starbucks having a coffe you can connect to their free wifi and you wouldn't use any of your data allowance if you had any