I need to download the 10.15 but I cant find it everything is like 10.15.1 and above

See: How to get old versions of macOS - Apple Support

Note: Use Safari to open the download links other web browsers may not work.

Hope it helps.

Q - " I need to download the 10.15 but I cant find it everything is like 10.15.1 and above "

A - That is because the user ( you ) are looking in the incorrect location.

Follow the very good advise from previous poster.

The Only FULL VERSION of Catalina offered from Apple is Catalina 10.15.7 and can be downloaded from the previous poster link.