It's never too late! You'll pick it up in no time if you put in the effort. By the way, 'may' is for asking for permission. It's 'can' in this case. Can I learn English? = Is it possible to learn English at my age? May I study here today? = Am I allowed to study here today? I'm also assuming 'having 30 years old' is 'tengo 30 años'? In this case, you either say you 'are 30 years old' or you're 'at the age of 30'. You can say 'I have 30 years of experience', though.

I started learning english at the age of 30, it was my first foreign language :))

Sí, puede aprender inglés a cualquier edad, si usted practica y corrige errores. Aprendiendo japonés, de hecho. (please correct my Spanish)

Comencé a aprender el castillano cuando tenía 30 años, y hora, tres o cuatro años más, tengo fluidez (más o menos) :o) Es difícil aprender su primera lengua extranjera. La edad es menos problemático, es menos un obstáculo. Salvo por el acento. Los jovenes pueden aprender acentos extranjeros más facilmente.

Claro que si! Also, you have to use the verb to be when talking about your age in English. In Spanish you would use the verb to have but in English you have to say "Can I learn English being 30 years old" or "Can I learn English even though I am 30 years old?"