As in English, vowels in Spanish are 5. The big advantage is that each one of them, unlike some cases in the English language, just have one unique sound, regardless of how it is used. These sounds are:
The only special consideration is that the letter U is also used beside the letters Q and G to form certain syllables. In such cases the letter U is “dumb”, what it mean that it is not pronounced. We’ll see this rule when we are talking about the syllables.
Moreover, and like in English, we have the letter “Y”. In Spanish also it works as a vowel or consonant as a function of where it is used. Its sound is identical to the letter “i”
And though it may seem elementary, here comes our first (and possibly one of the most important) TIPS:
You have to repeat till you drop, the pronunciation of the 5 vowels in Spanish, since their clear pronunciation and remembrance (alone or forming syllables) depends for you to achieve fluency, both in speech (and reading), as in listening. So do not stop practicing and becoming familiar with these new sounds and repeat ad nauseam as do the Spanish-speaking children in the first stage of education:
Do not be afraid to speak loud (for hearing to yourself), remember: you are learning a new language!