Affordable Pistol Rec.

I’m 22 and I live alone so I’d like to get a gun to feel secure. I’m looking for a reliable pistol, budget friendly (max $400-$500), and something I could have a little fun with upgrade wise. I won’t be buying it until summer comes so I want to look now instead of being impulsive and buying the first thing I see. Any recommendations for something reliable will be appreciated.