HomePod isn’t connected to Wi-Fi how do you connect

Depends on why it's not connected to WiFi.

If you're saying it's never been connected to WiFi, then start from the beginning and follow the setup instructions. It should go without saying, but make sure you have WiFi, that your WiFi router is on and working, and that you're placing the HomePod in a location where the WiFi signal is good. Also make sure your HomePod is plugged in to power. It doesn't have a battery. Here's a link to setup instructions: https://support.apple.com/en-us/HT208241

If it was previously connected to your WiFi but it isn't connected now, there a few things you could try. Assuming your WiFi is on and other devices are able to connect to it (including from near the location where you have the HomePod), unplug your HomePod, wait ten or fifteen seconds and plug it back in. After it initializes, it will probably reconnect. If that doesn't work, you might try restarting your WiFi router, as those sometimes will get discombobulated and need a reboot to refresh and reconnect everything properly.

If that doesn't work, you can try resetting your HomePod to factory settings and then set it up again as though it was new, using the setup instructions linked above. Instructions for resetting your HomePod to factory settings are here: https://support.apple.com/en-us/HT208244.

If none of that works, you probably should consider contacting Apple customer support.