I'm very new to OSM/OpenLayers. I having a hard time figuring out if it's possible to change the font of street names only.
I believe this downloads image tiles, so I'm not sure if this kind of modification is possible. Maybe it's possible to pull down an additional layer with modified street names that would overlay?
Any help appreciated
OSM tiles service is pre-tiled, you can't change the style of the tiles.
You have different solutions to achieve your goal:
1- Openlayers give us a way to connect to Mapbox data. I don't know really well Mapbox, but what I know is that there is an API to change the style of OSM data and render imagery tiles or vector tiles. So in this OL example you can see how it connect to the data and how it handles style
2- The hard way: You can make your own basemap with the data of OSM. You will need a database to store the data (PostgreSQL) and a map server to render the data and control the style, like Mapserver, Geoserver, Mapnik... there is many options for that.