Add a black outline to titles on gallery images

Hello. 

Im looking to make the text on my titles and descriptions of each gallery image white, and also add a black outline around the text to make it more visible. Can anyone help with this please?

Site is https://goombagrows.com 

Password: 123

I see top already has a white background, do you still need help?

I would prefer to remove the card/ white background and replace it with white text and a black outline around the text

Thanks for your response!