what are the 3 steps to conjugate a verb? .
3 things that you must know to conjugate the verb: person (according to the verb's subject), mood and tense. Other things would be whether the verb was regular, irregular, stem changing, had unique accent mark (like reír), pronominal, etc.
And, of course, you have to know the rules for forming that particular tense of that mood (the verb endings) for the verbs that are regular in that mood/tense or how to conjugate the auxilary verbs in the compound tenses.
If there were only 3 steps, conjugating verbs would not be the headache that it is for beginning Spanish students. I think that your question only pertains to forming the present tense of regular verbs of the indicative mood.
- separate the ar/er/ir ending from the verb infinitive leaving the verb stem.
- make any necessary stem changes if the verb is stem changing or irregular
- add the appropriate verb ending to the stem according to the person of the subject of the verb. (assuming present tense, indicative mood)