Locked out of my own phone by neighbor.

I accidentally left my cellphone in my carport. Should've been alright, but for a trespassing neighbor. Well, they changed my password and I can't get back into my phone. I can receive calls and answer them. I can't make one or access the phone itself, because I've been locked out by a password change. Yes, it was on at the time he got it. I had a long timeout because of what I was looking up and didn't want to constantly respond to keep it going. But, before it shut off he got it. Id thought it be alright on r I realized I had forgotten it there but was wrong. Anyhow I need back in to find out what damage they've done. I can't access my indeed, Gmail or Facebook accounts which I need to get the job I had applied for. The phone is a Nokia, not sure the model, but I'll try to send a picture.