See >>> Move from Android to iPhone, iPad, or iPod touch - Apple Support
A further option is to first transfer your photos to your PC using whatever method works best for you - and then use either iCloud for Windows, or iTunes for Windows, to transfer photos from the PC to the iPad.
1) Install iCloud for Windows on your PC. This will allow you to share and transfer your photos via iCloud.
Download iCloud for Windows – Apple Support
Set up and use iCloud for Windows – Apple Support
2) Install iTunes for Windows on your PC. This provides other transfer and management options.
Download and use iTunes 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.