I went to a friends house last night and connected my roku and left my remote at their house do I need it to reconnect to my home wifi?
Your Roku remote is the only way you can connect your Roku to WiFi
If it's a Roku Stick, then yes a Roku remote is required. If it's any other Roku player, you can get an inexpensive (under $10) universal IR remote that can control the Roku. Just make sure it lists support for Roku players on the package.
Depending on whether it is easier to go back to your friend's house and get your remote.
The Roku device will remember the last network is was connected to. You can call your friend and ask for his/her SSID (network) name and wifi password.
You then change these in your router to match those. Reboot your Roku device and it should connect.
Then you use the official Roku remote app available in Play/Apple stores installed on your phone to use as your remote until you get your physical remote back.