Here is a video explaining the dark L that might help:
American English Pronunciation - dark L
Interested in Language
well welcome, i'm glad to see another countryman in this website
Funny, I call them front and back /l/ with my students, which they find clear enough. To teach the two, I first teach the French and Russian /l/s, which are more strongly front and back pronounced than our own two /l/s in English.