Guelph Central Station is in downtown Guelph. It's good that there's no parking - we don't want to encourage people to drive downtown just to park their cars there.
Local transit doesn't need frequent service to be a competitive option to access all-day train service, since the trains will only run once per hour anyway. And based on the track configuration, my guess is that the trains in both directions will meet in Guelph, so a single bus per hour can connect to both directions of the GO train.
What's more important is good coverage from the station, and they already have that. The bus terminal has 20 bus bays, which makes it possible for up to 20 buses to be timed to meet each GO train.
The route network already provides excellent coverage across the city directly from the train station:
https://guelph.ca/wp-content/uploads/GuelphTransit_SystemMap.pdf
And Guelph Transit is free for GO Transit customers:
https://guelph.ca/living/getting-ar...ph-transit-and-go-transit-fare-integration-2/
To further improve coverage from the station, particulary for people outside Guelph, GO could run a route to Elora and Fergus (currently there's just one bus per day). Guelph Transit could also set up park-and-ride lots along the main Route 99 bus corridor, potentially including express service.