WHY MY NEW MACBOOK DOESN'T HAVE OFFICE INSIDE AFTER BUYING IT VERY EXPENSIVE LIKE THAT AND THEY ASKED ME TO BUY IT FROM APPLE STORE

If you want Microsoft Office then purchase it, MS Office has never can with a Mac and it does not come with PCs. Sometimes PCs come with a frer trial period of MS Office

Microsoft Office is a Microsoft product, not Apple.

You bought an Apple Mac with includes

Pages: a word processor, Numbers: a spreadsheet, & Keynote: a presentation app.

If you cannot use those free apps from Apple then you have to buy MS Office from App Store.

You can purchase it from Microsoft (or subscribe): https://products.office.com/en-us/buy/compare-microsoft-office-products?tab=omac

Another option that may or may not meet your requirements is LibreOffice. It is free and very good. https://www.libreoffice.org/

Microsoft does offer an online version of Microsoft Office for free.

See the following link: https://www.office.com/