how to sync IPad and computer together

Assuming that you have a Mac computer, you’ll be able to synchronise many Apps and services via iCloud. To do so, both your iPad and Mac must be signed-in to iCloud with the same AppleID. The iCloud User Guide provides information and guidance:

How iCloud keeps information up to date across all your devices - Apple Support

If instead you have a Windows PC, your options are limited…

To synchronise or transfer files directly between iPad and a Windows PC, you will need to install the most recent version of iTunes for Windows:

Download and use iTunes for Windows – Apple Support

Update to the latest version of iTunes – Apple Support

If you simply wish to exchange files and photos with the iPad from the Windows PC, you might instead consider using iCloud for Windows. When signed-in with the same AppleID, you can simply use iCloud to exchange or synchronise files:

iCloud for Windows

Download iCloud for Windows – Apple Support

Set up and use iCloud for Windows – Apple Support

You can install and use both on the PC. They will happily coexist - and provide considerable flexibility in how you move/share/transfer photos and other documents and data between iPad, iPhone and your PC.