What to do after an accident?
The highway code has some advice on First Aid on the Road. It says:

1. Deal with danger - the cyclist was on the pavement and the van was parked, so you did this.

2. Get help - an ambulance was called, so you did this.

3. Help those involved - you didn't move the cyclist and you kept him comfortable, so you did this.

4. Provide emergency care - you don't mention what injuries the cyclist had, but it sounds like you didn't need to do this.

I don't think you missed anything crucial, assuming the cyclist didn't have serious injuries (e.g. heavy bleeding).