Q&A for How to Open a Terminal Window in Mac

Spotlight is used mainly for finding apps quickly. It is much faster then the dock and to use it, just press command and space.

You can find uninstalled apps that you purchased from the App Store by going clicking on your profile picture in the bottom left corner of the App Store and then by seeing purchases.

It looks like you have it in Login items to startup on boot. To fix this, open System Preferences, then Users, then choose the User you log into, then Login items. It will display a bunch of apps. To change it, first click on bottom left padlock and enter password to be able to edit settings. Next, select Terminal and/or other apps and press the "-" sign just below the box. That's it. Try restarting and check.

Your Mac might have automatically updated to newer version of Mac OS. If you don't like it, you can't do much about them, as they are system apps which can't be uninstalled.