Hello totalbeginner
Click start and type Windows Defender(in the Search just above the Start Orb).
From the tools, click on the Software Explorer.
Change the dropdown to startup programs, then click on one of the programs that is blocked from the list.
The 'enable' button on the lower right should become an option for you to click.
Note
You may need to click the "SHOW FOR ALL USERS BUTTON" at the foot of the page.
This will activate the Remove-Disable-Enable buttons when you select a program on the list