Play with the settings before you start, if I want a relaxed play around, I'll set competitors to zero, breakdowns to never and stuff.
Then I'll find a nice area with a few towns close by and connect them with roads. Then I put bus stops in the centre of the towns, the ones you put on a road. Between the towns, I put a depot and buy a bus. Then you have to tell the bus to go to each bus stop, and send it on its way.
Then I have a basic income, and I look for industry and resources to truck around. Later I play with trains and ships and airports and supply chains and stuff. But I keep the busses going.
If you want early cash, the best way is to connect coal. It's literally just an A-B train, and you rake in the cash. It's much more lucrative per dollar spent, which let's you focus on whatever else you want to do, like buses, planes, etc.
Tutorial: or everything into airports and long-distance routes, you'll make more money than you can spend. 🤷 At least, that's how it was when I stopped playing it.