Teaching Spanish irregular present tense can be a little confusing. Try not to teach these verbs until your students have a strong grasp on conjugating regular verbs.
A common lesson taught when teaching the irregular present tense is the irregular YO forms. Here is a Power Point that teaches these.
This is a great video by the infamous Sr. Mara taking on the irregular present conjugations:
While you’re teaching the irregular verbs here is a simple video teaching the SER conjugations: