I Come From USA Or I Came From USA- Which One Is Correct?

 I Come From Or I Came From

Both are right but you can't use them everywhere. Grammatically, I come from (Present Tense) and I came from (Past Tense).

Yes, you are correct that "I come from" is used in the present tense and "I came from" is used in the past tense. "I come from" is used to indicate one's place of origin or where they currently reside, while "I came from" is used to indicate where one was before a specific point in time.

In the examples you provided, "I come from Bangladesh" is the correct way to respond to the question "Where are you from?" because it indicates where you currently reside. Saying "I came from the USA" would imply that you are no longer living in the USA.

In the second example, "I came from school" is the correct way to respond to the question "Where did you come from?" as it indicates where you were before you arrived home.

It's also worth noting that "I am from" is also a common way to express one's place of origin, but as you mentioned, it can be considered more formal or less interesting than the other alternatives.

I Come From

For Example, You are an international student. You have gone to the UK from the USA. Now another student asks you "Sam, Where are you from?" You will probably say "I came from the USA"  This is not the right pal.

You have to say "I come from Bangladesh" You can also say "I am from Bangladesh" but it's kind of boring. Expand your vocabulary.

I Came From

This is also right but you can use it in some specific place and specific time. If you know the right use of it listener will be more impressed. 

For Example, Your mom asks you "Sam, Where you came from?" You can say "I came from school"