I used to do a few days here and there in a local cycling café if they were short staffed or busy and I used to bake for them as well.
The problem with cyclists is that they tend to arrive in groups. So the café is dead, dead, massively busy rush, dead.
That means you need food that is quick and simple but good. Stuff that can be done in bulk so if you’re doing one serving of it, it’s just as easy to do 6 servings.
Soup in a big tureen, a big grill for doing a shedload of bacon or fish fingers at once, that kind of thing. Fish finger sandwiches were always really popular and any sort of egg was a winner and pretty easy. Scrambled or poached. That then offers combinations – cheese, egg, beans, bacon on bread / toast or any combination of for very little extra work.
Good coffee is essential as is having the staff who know how to use the machine. You may think latte art is poncy but it shows an experienced barista who takes pride in their work and will go the extra mile to make a really good cup of coffee. And coffee is an easy profit margin and the thing that most people are likely to pop in for. For every person ordering a meal, there’ll be 3 or 4 who just want a coffee and a slice of cake.