Quick check
Tap a Spanish word, then its English partner
gustar runs backwards
English: I like the concerts. Subject is the person.
Spanish: Me gustan los conciertos, literally "the concerts please me". The thing liked is the subject and the person is an indirect object.
So the verb agrees with the thing: me gusta el concierto but me gustan los conciertos.
The trap: Yo gusto los conciertos means "I am pleasing to the concerts". Never conjugate gustar to match yourself.
gusta with one thing or any verb, gustan with several things
gusta + a singular noun: me gusta el chocolate.
gusta + an infinitive, always singular no matter how long the phrase: me gusta comer comida picante, nos gusta ir a los conciertos.
gustan + a plural noun: me gustan los chocolates.
The trap, and it is in your own notes: nos gustan comer comidas picantes is wrong. A verb can never make gustar plural. Write nos gusta comer comidas picantes.
The A mi is optional, the me is not
The full form doubles the person: A mi me gusta el cafe. The a mi adds emphasis or contrast and can be dropped; me cannot.
A mi me · A ti te · A el / a ella / a usted le · A nosotros nos · A vosotros os · A ellos / a ellas / a ustedes les
With a name, the a is compulsory: A Guillermo le gusta el pop.
The trap: Guillermo le gusta without the a is wrong, and so is a mi gusta without the me.
tambien agrees, tampoco agrees with a negative
Me gusta el cafe. A mi tambien. Me too.
No me gusta el cafe. A mi tampoco. Me neither.
The trap: English says "me too" in both directions in speech. Spanish will not: after a negative you must switch to tampoco.