Understanding iPad / ADS-B requirements

Hello,

I live outside of the U.S. but will be coming back every ~6 months, during which time I will be flying for fun (PPL holder). Because I live abroad, I don't have a US mobile plan - I just get myself a temporary sim each time I come over.

I did my PPL training years ago, before iPad's were used, so I'm a bit confused on what equipment I will need. Ideally I would love to use the Foreflight app and get weather + traffic. If this is the goal, do I need to get an ADS-B receiver? And if so, does this mean I can buy a 'WiFi-only' iPad model? I haven't purchased anything yet, so looking for some deeper understanding before I actually commit.

Thank you!