I use present tense mostly but with occasional past tense here and there in my chapters.
So, if the story is in 1st POV- past tense or present tense?(third POV with present tense will be a bit weird, tbh)
Both. But not at the same time. Ai-chan picks either past tense of present tense for the whole story.
Ai-chan's personal opinion is that whenever you want to portray something that happens as it happens, you use present tense. If you want to tell the story as a life experience, you use past tense.
Neither is wrong, it's just that in English, stories are traditionally told in the form of "Once upon a time". In Eastern languages, stories are told in present tense, because most eastern languages do not have a past tense form of the verb, you have to add a word to inform the listeners that it happened in the past.
So instead of "happened" as in English, in eastern languages, it's "once happen". So Ai-chan is more confortable with present tense because English is not Ai-chan's first language.
As for the POV, Ai-chan uses all three, though not at the same time. 1st person POV when Ai-chan wants to make the reader put themselves in the protagonist's shoes. 2nd person when Ai-chan writes a more involved in-your-face kind of story. 3rd person when there are more than one protagonist.