There are 13 verb tenses in English.

Present simple = I walk to work = This is for habits, general truths, and for things that are happening now.

Present continuous = I am walking to work = This is for actions happening right now.

Present perfect = I have walked = This is for actions that started in the past and continue into the present or completed actions with a present consequence.

Present perfect continuous = Actions that started in the past and are ongoing to the present = I have been walking

Past Simple = Actions that started and finished in the past = I walked to the bank and withdrew some money

Past Continuous = Actions that were ongoing at a specific moment in the past = I was walking to the bank when I remembered it was Sunday

Past Perfect = Actions that were completed before another action took place in the past = I had walked to the bank before taking an Uber to the store.