In case you haven't already grasped "gustar", I did this and I really, really hope it is helpful for you!!
Forms of gustar:
gusto (I am pleasing)
gustas (You are pleasing)
gusta (He/She/You-formal/It is pleasing)
gustamos (We are pleasing)
gustaís (You all-informal are pleasing) // By the way, I've never seen this form; just guessing
gustan (They/You all-formal are pleasing)
Please note that you will almost never find any of these just by themselves. That is, without a me/te/le/les in front of it... as far as I know
Now, what the me/te/le/les signify is unto whom something is pleasing
Me gusta ____
Literally: Unto me it/he/she/you-formal is pleasing
Translated as: I like it/him/her/you
So: Me gusta la música --> Unto me (or "to me") [the] music is pleasing --> I like (the) music
Me gustan _____
Literally: Unto me **they are pleasing*
Translated as: I like them
So: Me gustan los perros --> Unto me [the] dogs are pleasing --> I like [the] dogs
Let's try somemore, huh?!
- Le gusta : Unto him/her/you-formal/it it is pleasing
A María (to María - emphasis & clarity), le gusta el churrasco : To María, unto her the steak is pleasing : Maria likes the steak
- Nos gusta : Unto us it is pleasing
Nos gustan las películas : Unto us movies are pleasing : We like movies
Les gusta : Unto
them/you-all-formal it/he/she is
Les gusta el fútbol : Unto them/you-all-formal soccer is pleasing : They/y'all like soccer
Te gusta : Unto you it/he/she/you-form. is pleasing
Te gusta a María : Unto you María is pleasing : You like María
Wow, that was a lot. One last one!
For the example you gave: No les gustas a mis padres
Unto them (my parents) you are not pleasing
My parents don't like you (lol)
Well, I hope this really helped. Also, if anyone sees any mistakes I made (critical or trivial), please feel free to correct me! Thanks!