Simple answer: NO!
More in depth:
ISP/SP (Service Provider) supply/install ONT (Optical Network Terminal) box needs power & earth ground. Also keep in mind your landline (POTS) feeds from ONT as well. All ISP/SP ONT boxes offer coax (TV) and an RJ-45 (WAN Port to Firewall/Router)
If possible, provide a fiber path into your garage (Cleaner install). If you're not into DIY call an electrician with network cabling experience.
Yes, you can have fiber (Patch cord) from ONT connecting what's called Pro-Sumer product like Netgate 2100 pfSense firewall/router running snort pfblocker, Suricata. (Guessing it's not something you need).