It will depend on what you want in the garage. Do you want a single device connected (and is that wired or wireless), or do you want to connect multiple devices?
If it’s a single device then power line might work, you need to connect both ends to the same mains circuit for the best performance, and they tend to be a bit hit and miss. I would get them from somewhere you can return them if they don’t work, or borrow some and try them.
You can get Wifi Extenders that pick up and then repeat the wireless signal, how good that would be might depend on where the current Wifi point is in the house, and using that full-time may well drop the wireless performance in the rest of your house (as it might connect at a low speed and pull the rest of your connections down to that speed)
If you want to connect multiple wireless devices in the garage then you will need another access point in the garage you can get these as wireline, Wifi extenders or that just connect via ethernet.
The best option would be to run an Ethernet cable to the garage.
PM me if you want to take the conversation further