Automatically launching everytime I insert a memory card

Hi @katherine_4593, welcome to the community!
To check if Lightroom is set to automatically open on your Mac, try this: connect your memory card to your Mac, then open the Image Capture app (you’ll find it in your Applications folder). Once it’s open, select your memory card or camera from the sidebar. In the bottom-left corner of the window, click the small icon that looks like a triangle or eject symbol. From the menu that pops up, choose “No application.” That change will save automatically, and Lightroom should stop launching when you insert that card or device.
Hope that helps!
Alek