In principle, a petrol water pump requires very little maintenance. However, you should always pay attention to the instructions in the user manual.
Also make sure that there is always enough oil, otherwise this will damage the engine. Once a year, you should also change all the oil.
Also clean the housing regularly and check that all connections are tight. If not, replace the leaking seals with new ones.
Also, make sure that the water pump is not exposed to frost. Find a suitable place where you can store the pump frost-free in winter.