Maybe you have referrals in "Coinbase Earn"?
Here's the help center article about it: Coinbase Help Center->Getting started->Coinbase Earn

But if you're positive that you shouldn't be receiving any transactions, then start investigating if you're really using Coinbase app
and not a fake app where a scammer is in control of the wallet and just waiting for you to deposit a relatively large amount.
These are the links to the correct app:

• Android: https://play.google.com/store/apps/details?id=com.coinbase.android
• IOS: https://apps.apple.com/us/app/coinbase-buy-sell-bitcoin/id886427730