So the first step would be to draw them all out. It may help to work outwards from the double bond bc there's some branching involved, and it will also allow you to spot geometric isomers a bit faster. After you've done that, you kinda have to do it by process of elimination.
So first you want to eliminate the ones that physically can't have geometrical isomers, i.e. when you've got two identical groups on the same side of the C=C bond. For example ethene-1-ol (if such a thing exists) couldn't have geometrical isomers, because there's two hydrogens on the same side of the C=C bond, so if you flip the groups you end up with the same chemical you had previously.
After that, you want to check if the chemical(s) which display geometrical isomerism also have a chiral centre (ie there's a carbon with 4 different groups coming off of it like you said). That should leave you with one option