Because campaigning works differently across the globe. So does media coverage and politics and how the different parts of legislative share competence/responsibility.

I’d say you need to follow local news and what happened in the last years to make an informed decision. See which party/politicians built children’s playgrounds, did something useful for the community and which major tore down the shops in the city center to make space for more lucrative office buildings… It’s really difficult to tell if you don’t know what’s happening around you but just following world politics. (And local newspapers are long gone, so that’s another hurdle.) Where I live they have some scarce information online. And you can also go to them once they go campaigning and listen to them or read some advertising material.

A big part of my decision is the party they’re part of. At least when I never read their names before. I’m also not affiliated with one specific party, but I certainly know if I’m conservative, religious or progressive and whether I care for the environment and other people. So I can base my decisions on that and whether their party cares for the things I deem important.