I lived in my own home for decades with a garbage disposal in the kitchen sink. Now in a rental with no disposal and sometimes I forget that I have to baby the 20+ year old rental house stuff.... Anyway, I dumped ~1 cup of crushed pineapple down the drain & it has not completely & freely drained since then (about 2 days ago.)

What are the steps I should/could take to attempt to clear it & when do I call the rental company to deal with 'it'?

Thank you!!

easiest first step is a good old plunger..

Unless a plunger works, if you are a tenant, stop there, call the landlord and tell him the truth. You are not allowed to touch his plumbing and if something goes wrong, he will hold you liable

It may be lodged in the trap, and the last thing you may want is to use a plunger and push it further down the drain.

if you are handy, disassemble the trap and put a 1/4 inch retriever snake in to remove the Pineapple. Fiberous stuff is your enemy and for best results put in the trash.

I'm having a little difficulty seeing crushed pineapple passing thru a basket strainer in a kitchen sink. Even so, it's probably lodged in the end waste or trap. I'd remove those and manually clean them out.

Call the rental company. Do Not try to take anything apart. A lot of stuff can go wrong and then you will be blamed for making unauthorized repairs.