There are many differences between “nos le gustan” and “no le gustan”. As S.C. mentioned, the former is not grammatically correct.
It is easier to grasp if you respect how the language is assembled. These sentences are reflexive. The literal translation of “no le gustan” is not “doesn’t like them”, but rather, “they are not pleasing to him”. In “nos le gustan”, the subject is not “we” (nos), as it would be in English; it is whatever we are trying to say we like. That is why the sentence does not make sense, as “le” is singular and “gustan” is plural- they don’t agree. If you want to say “we like him”, it would be “nos le gusta”, or to say “we like them”, it would be “nos los gustan”, or “nos las gustan (fem)”.
No and nos are not similar in any way but spelling. No means no. Nos means “we”. With the second sentence, the subject is understood within the verb. In English, this is done only in commands; in all other contexts, we must say the subject. In commands like “stop it”, “come here”, or “Help”, the subject is understood as “You”: “(You) stop it”, (You) come here”, or the double omitted, “(You) help (me)!”
So, in the first sentence, “gustan” actually means “they are pleasing”; “le” is the object “him”. “Le gustan” is “He likes them (they are pleasing to him). No means no; putting “no” in front means he doesn’t like them (or “they are not pleasing to him”). If you want to say “We don’t like them” instead of “he doesn’t like them”, then it would be “No nos les gustan”. “I like it” = “Me gusta”.
You want to conjugate “estar”? It is an irregular verb, just as it is in English, “to be (location)”. Do not ignore the accents when conjugating; they are important to identify the tense, and word. “Está” means "(he, she, or it) is", while “esta” simply means “this”.
In English, “to be” is irregularly conjugated as: I am, you are, he is, we are, you (pl) are, and they are. If it was a regular conjugation, it would be conjugated as: I be, you be, he bees, we be, you (pl) be, and they be. Obviously, this sounds very silly. The same is true in Spanish when not correctly conjugated. In Spanish, “estar” is irregularly conjugated as: estoy (I am), estás (you are), está (he is), estámos (we are), estáis (you (pl) are), and están (they are).
“Estar” is used in Spanish as we use “to be” in some contexts. “Estar” only has half of the meaning that “to be” does; many of the other meanings are expressed by the verb “ser” (also irregular). “Estar” is used to express a temporary, or not lasting, condition (like “I am busy” = “estoy ocupado”). A permanent, or lasting, condition (like “I am Drama8888”) is expressed with “ser”. “Estar” is used to express location (also temporary), like “I am here” is “estoy aquí”; “we are here” is “estámos aquí”; “she is here” is “está aquí”. “Estar” is also used in progressive tenses; “I am walking” is “estoy caminando”; “you are learning” is “estás aprendiendo”; or “they are bothering me” is “me están molestando”.
When speaking in Spanish, the English speaker must break down the meaning of what we are trying to express before we can determine the correct use of “estar” or “ser”. The reverse is true with “hacer” in Spanish, because in English, we use 2 verbs to express what “hacer” does in Spanish (“to make” and “to do”). If a Spanish-speaking friend calls you up to see what you are doing, they might say, “Hi, what are you making? (¿qué haces?)” instead of “what are you doing? (still ¿qué haces?)”. It is just as silly to mix up “estar” and “ser”. These are the considerations of a non-native speaker, as a native speaker can tell if it is correct simply if it sounds silly or not.
Being Mexican or Spanish does not automatically make you an expert of the Spanish language, just as being English or American does not make you an expert of the English language. One must formally study the language in an academic setting to understand the methods of syntax and the purpose of lexicon.
Studied Spanish in grammar school, high school, and University
Studied Spanish in Spain, Mexico, New York, Southern California, and the Carribean