I am basically level 1 new and don't even know what words to use to start
Basically I want to build a simple door alarm, everything I found costs hundreds of dollars for anything that might do the stupid simple thing I need

Basically I want to make a little device that is battery powered that beeps when it's connection is broken but turns off when the connection is made
Something that goes "annoying loud beep" 2 sec pause "annoying loud beep" until the door is closed
A basic on/off beeping device where on is when the connection is broken and off is when the two sides are together
Hopefully one of these phrasings make sense

I have all the tools I think I need to make it, though no idea on the supplies or where to find them
I can 3d design and print the housing case, and I have a soldering tool, though I need to get some appropriate solder but not sure what kind I would need

 

The easy route is to use an LM555 timer IC. You'll need two to do what you want, I think. To turn device on/off, use magnetic switches.

 

A happily annoying beep beep every time family members enter or leave.

Unless you live alone.