I'm not going to invite coworkers to a funeral/not going to funerals of coworkers' families
Why would you not want to go to a coworker's family's funeral?
I hate funerals, I think they're boring
You don't have to like funerals, that's normal. But be kind and support your coworkers and go when invited.
There is something wrong with you, funerals are boring.
I am sure it would mean a lot to your coworker for you to go to the funeral whether you enjoyed it or not. The funeral does not have to be fun, just go as a way to show respect to your coworker and their family.