What are you studying?
There are not many conjugation rules at all. This is a myth (the varying conjugations and difficulty come from varying the level of politeness, which you as a beginning learner and a foreigner have no need to do). Forgetting irregulars, and assuming you're focusing mainly on using an informal polite speech (요 as an ending, as in, 잘했어요) (which you should be, because it's the most common and is acceptable in any context), present tense has ONE RULE. If the verb stem ends in 오 or 아 then it conjugates to 아요. If it is any other vowel, you use 어요. Same with adjectives.
Example: verb = 먹다 (to eat) 다 is similar to adding "to" at the beginning of a verb in English and it is called the infinitive. The piece before it,먹, is the stem. The vowel in the stem is not 오 or 아 so it conjugates with the 어요 ending. 먹다 becomes 먹어요. 저는 피자를 먹어요. I eat pizza.
What about words with more than one syllable as the stem? Look at the vowel in the final syllable.
The place where this gets tricky is with certain vowel combinations, but don't stress about those if you haven't been able to get the basic structure down. Deal with the BIG CONCEPT first, then worry about nuance, challenges and exceptions. It's OK to be wrong sometimes.
The only other basic, fundamental rule to Korean conjugation and particle use is knowing whether the word ends in a consonant or a vowel. 을/를 -> If the word you are attaching this particle to ends in a consonant, you need a vowel to follow it, 으 is a vowel, so 을 would follow a consonant. If it ends in a vowel, then it needs a consonant to follow it, as in my example from above, 저는 피자를 먹어요.
Two rules. Pretty easy, right?