You can purchase a book with sample questions from Amazon and other locations.
This one seems fairly popular "OCA / OCP Java SE 8 Programmer Practice Tests by Scott Selikoff and Jeanne Boyarsky" and both of the authors are on this site frequently.
If you want, you can spend $10 and get over 500 practice questions from Enthuware,
Post by:Pete Letkeman
, Saloon Keeper
Please note that you will not find any explicit exam questions on this site.
The best that you can do is to get exam like questions.
These questions could be really close to the real thing, of very far off from the real thing.