How do I combine multiple lines of information into a single cell, separated by commas?

Hi. I'm pretty new to advanced Excel functions, hopefully someone here can help me out.

I have a list of names in column A and I would like to combine them into a single cell with the names separated by commas. I've attached my worksheet. This one only has 366 names but the one I will be working on next will have a couple thousand I would like to avoid naming each individual cell manually if possible. If someone has a shortcut that would be awesome.

Thanks!

Copy of schoolboard full.xlsx

That worked perfectly, thanks so much!!!

I pulled this list from our database which exported a long document with lots of columns(which is why it is set up like this to begin with). I'm creating a form and I need to have a drop down option where people select which school board they belong to. The generator that I'm using to create the form only accepts values separated by commas. Next I need to create a drop down for every school in the country! You've saved me a ton of time, I knew there had to be an easier way to do this in Excel.