Hi fajok85102
If you choose the DublinCore metadata template, you should already have 15 metadata already set up for your use. We can say that DublinCore is a standard that can be used as a basis for many cases. Then you can add metadata that are specific to the objects you are dealing with.
Your case is also the basis I started from when I created the collections portal of my university. I had to be able to record physical objects, laboratory devices, musical instruments, minerals, fossils, artistic works, photographs, archival documents, musical scores, vinyl records and even trees... I chose DublinCore and added metadata specific to minerals, fossils, trees, scores, etc.
By default, there are already many types of possible relationships between these objects, or between objects and places, individuals or legal entities, events (occurrences), collections, storage locations, lots... But we can also customize these links to adapt to the particular case.
CollectiveAccess is a great software that can do a lot of things. It can be difficult to get started with at first, but it is worth the investment.
Bye.