Learn Object Pascal to learn Object Pascal. Learn Java to learn Java.
Object Pascal is the best way to create cross-platform desktop applications. It has the most sensible and readable syntax, and can do everything C++ can do, without taking a decade to master. I used to use C and C++, but got tired of juggling razor blades.
Unfortunately, despite its merits, Object Pascal is not high on requested job skills. If you want to get something done targeting cross-platform desktops, quickly with minimal stress, use Object Pascal. If you are looking for a job, you may need to learn what ever language of the day has a high profile.
I am lucky that I write software as a one person team. My users only care if it works. It does.
BTW, I am quite a bit older than you.