What did you vote in the past? CD&V/CDH? Groen/Écolo? sp.a/PS? Hard to give you some pointers without knowing where to start.
Voted Groen on the local election in Octobre, this is my first Flemish/national/European election.
Pros and cons for each of the Flemish parties are to me:
NVA: + Seems to be the most rational and levelheaded overall, - too right on a lot of issues (climate, economy...)
CD&V: + is the most centrist party, - too traditionalist and religious, their main goal seems to be to get votes from relgious people
Groen: + cares the most about the environment, - is the most politically correct
Open VLD: mostly similar to NVA, + they're less conservative, - they're even more libertarian when it comes to climate and economy
SPA: mostly similar to Groen, + they're slightly less politically correct, - they're slightly less green
Vlaams Belang: - they're the far right version of NVA
PVDA: - too communist, far left