Memorize the Spanish vowel sounds, and you will be able to speak most Spanish words with surprising accuracy. The "a" vowel sounds like the word "ah," the "e" vowel sounds like the word "eh," the "i" vowel makes a "long e" sound, the "o" vowel sounds like the word "oh," and the "u" vowel makes a "double o" sound like the word "oops."
Practice saying the Spanish vowels over and over until they roll off your tongue without having to even think about it. Having these five simple letters down will enable you to pronounce at least some part of any Spanish word already, sometimes even all of it.
Sound out most consonants exactly how they look. Every consonant is said the same in every word. This is much simpler than English.
Learn these few exceptions to consonant sounds. The letter "h" is always silent. The letter "j" is pronounced like the English "h" sound. The double consonant "ll" sounds like the English "y" sound.
Roll the double consonant "rr" with your tongue, if you are able to accomplish that feat. It might take some practice.