Verb tense can be a very simple thing, or a very complicated thing, depending on the situation. I'm including a link to Oxford Dictionary's definition of verb tense, there are six. I divide these into two categories, simple tenses and perfect tenses. Perfect tenses are passive by nature, and as my 5th grader can tell you passive means helping verb. Regardless of which tense you choose it should always match.
Simple Tenses: Present, past, future. These are the simplest forms of the verb and it should be noted that future tense the word will or shall needs to be used to complete the future tense.
Perfect tense: narrow the range of a specific verb to a moment in time. Present Perfect-- something is happing, Present Past--something has happened, Present Future something will happen.
There is one more tense, the continuous tense, but most novelist will have no need to use it. Continuous tense uses three verbs in a row and denote an action that is ongoing, has been ongoing, or will be ongoing. Used with the present participle of the verb (the verbs ending in -ing), it gets confusing in narration pretty fast. Typically, if continuous tense needs to be used, it will be used when a character is speaking, when all rules of grammar can pretty much go out of the window.
For clarity's sake I'm going to leave you with a few examples below. Have you struggled with verb tenses in your work? Leave a comment in the section below.
Verb Present Past Future Present Perfect Past Perfect Future Perfect
to be be been will be has been had been will be
work work worked will work has worked had worked will work
run run ran will run has run had run will run