What is an API? What is an API?

Don’t worry, I don’t know what is that means tooeither. Don’t worry, I don’t know what it means either.

Yesterday, I wanted to learn some new knowledge about Excel. Yesterday, I wanted to learn some new knowledge about Excel.

The best teacher will beis YouTube because it is free. The best teacher is YouTube because it is free.

In this case, it is more appropriate to use present tense ("is YouTube") because YouTube is the best teacher in the present.

One video is teachinges you how to get a data source from “an API”?. One video teaches you how to get a data source from an API.

I can assure you that you will be surprisinged at how manyuch information you can it get from this API. I can assure you that you will be surprised at how much information you can get from this API.

"many" is for countable objects, "much" for uncountable quantities (in this case, information).

Many Ggovernment’s' data bases, stock markets…. Many governments' databases, stock markets….

even the temperature ion Mars too. even the temperature on Mars.

Because you used "even" to provide emphasis, the word "too" is redundant.

Based on such information and using Excelone can make a really professional presentation using Excel. Based on such information one can make a really professional presentation using Excel.