Text Alignment in Carousel Cards

I'm trying to get the text to be left aligned inside of these carousel cards, but there is no easy way to do it in "Edit Content" > "Design" when clicking on the block. I have very little knowledge of CSS, but I was able to change the paragraph text alignment. I can't seem to figure out how to do the same to the header. I've tried h1, h2, etc but none of them work. Any ideas?

Here is my code so far:

(I am missing the number for h in the screenshot, also as a part of trial and error)

Also, is it possible to add this green line underneath the header on these cards?

Can you share link to page in screenshot? We can check easier