I have a pretty long run, 180' from house (where 1 router is) and where my garage router is. I used outdoor cat6 and pulled it through a buried PVC conduit I had dedicated to cable/ethernet. That conduit runs in the same trench as my 200 amp service.
It works very well, can use "dish TV" and internet in garage, no interference or issues.
Cat6 Direct Burial, Waterproof, Outdoor Rated CMX, Black, 23AWG Solid Bare Copper, 550MHz, ETL Listed, Unshielded UTP, Bulk Ethernet Cable off amazon. I ordered a 500' spool for some stupid reason, but I certainly had enough.
You don't need to use fiber unless you are 300+ feet for 1gbe (or 150 feet for 10gb). I'd stay away from an overly-complicated fiber setup. I've seen media converters / fiber in action at work and they work lovely for 1000 foot runs, but the media converters will occasionally fail too. Not worth it for garage internet.
Wifi works, but nothing beats a hard-line for security, speed and reliability. If you are day-trading stocks in your garage run a cat6e
