RepNofitfy works for simple types (booleans etc) but not for blueprint classes

I realize that there’s probably something that I need to do to my class to make sure it can be send properly for replication but being new to unreal engine I have no idea where to start? Do I need to make them serializable or in some other way allow them to be replicated? Is it only possible to replicate simple types? I’ve searched high and low for this and have been unable to find the answers.