How often and what's included on a service really depends on both the make and model of the car and whether it's diesel, petrol or electric. And the annual mileage.
But typically you have a minor service and a major service.
Minor includes an oil and filter change. That's it. Besides topping up screen wash, checking the tyres, etc.
Major includes oil and filter change. Then a brake fluid change, air filter and pollen (cabin) filter. If its diesel it'll have a fuel filter as well. If its petrol it'll have spark plugs instead.
Major is recommended by some manufacturers every two years. Having the minor done in between.
Personally, I just have the minor (oil and filter) every year. Then do the major every 3 - 4 years.
I do recommend at least having the oil and filter done yearly.
You can ask the skoda garage to print you off a service schedule. They'll tell you what skoda recommends for you specific vehicle. It will tell you when stuff like wet belt, timing belt, etc. Are due as well as normal servicing If your car has a timing belt it's usually 10 years or a certain amount of miles. That is something that really does need to be done.
You can just get somewhere like Halfords to do your yearly oil and filter though. Will be much cheaper.