Google Mobile Services
None of Huawei's newly released handsets come with Google Mobile Services, which includes vital apps like the Play Store, due to restrictions placed on the Chinese manufacturer that effectively ban US companies from working with it without approval.
Unfortunately, these restrictions mean that Huawei's newest handsets, like the Mate 40 Pro and P40 Pro, are relegated to using the company's in-house AppGallery instead of the Google Play Store. While that doesn't make using these phones impossible, it's not by any means a complete Android experience. It's a whole lot more fiddly, challenging and less convenient than just buying yourself a phone that isn't restricted. Given some of Huawei's phones cost upwards of $1,000, it's hard to recommend buying them unless you're committed to the ecosystem.
Some of Huawei's older phones, like the P30 Pro, still have Google Mobile Services. So on those handsets, you're free to install as many apps from Google Play as you like.