Q: if i delete something in one computer will it be deleted in the other computer that i was sharing with the Home sharing??

That depends on specifically what you do.

Best thing to do if you want your media on the new computer is to copy the ENTIRE iTunes folder from the old computer to the new computer.  Now you have a backup copy of the ENTIRE iTunes folder.  Having a backup is always a good idea.

Use Windows Migration Assistant to copy all your user date to the MacBook.

See this -> About Windows Migration Assistant.

Using Home Sharing will transdfer the media files, but not the entire library (ratings, date added, artwork, playlists, etc.)

And as diesel vdub metioned, backup BEFORE you do anything.