I accidentally erased my messaging app on my zte tracphone, how do I fix it?

I was messing around in my settings and I accidentally erased my clock, calendar, calculator, and messaging. I went back to the settings to see if i could enable it but where I pushed disable, was gone, I couldn't click on anything. This is on my zte tracphone, I need my messaging app and my clock. Please help me, I don't know how to fix this.

Welcome to the forums. Usually system apps need to be reloaded by reflashing the stock ROM. However, Google has basic versions of Messaging, clock, and calendar. There are a lot of calculator apps on Play as well.