In the Google home app, in the very top, there should be some colorful circles that say things like "routines," "media," etc depending on what you have on your network. There should be a circle that says "wifi." Click on that circle and it will bring you to a page similar to the old Google wifi app where you'll find your devices, speed tests, and other controls from the old Google wifi app.
Same here. I'm guessing your Google Home and Google Wifi apps were registered to separate email addresses. That's what happened to mine, and I'll be damned if I can find a way to get them under one roof, because inviting one to the other always ends with "Can't send invite right now Try Again"! Really hating me some Google.