What's the best way to learn verb conjugation?
Start by learning the rules for conjugation of regular verbs(-ar, -er, -ir) in the present tense.
Also, in Spanish, it is good to start early with some irregular verbs because some of them are the most common/useful verbs in the language.
Once you have a good understanding of the present tense, learn the rules for conjugating regular verbs in the other Spanish tenses. (preterite, imperfect, future... etc)
The app Spanish verbs sea game I found to be helpful as well as another just called Spanish verbs. Also a youtube playlist on verbs from a youtube channel called The Spanish dude. He has a site called gringoespanol and offers many free vids and exercises as well as premium ones.