Yes, you can.
Can you use "come across" to express the idea of finding a place unexpectedly instead of running into someone? If not, is there any phrasal verb or idiom that you can use to express that idea?
Yes, you can.
You can also say:
- found myself at/in
- ended up at/in
- wound up at/in
Old-fashioned expressions:
- chanced upon
- happened upon
I'm not a teacher. I speak American English. I've tutored writing at the University of Southern Maine and have done a good deal of copy editing and writing, occasionally for publication.
And also
stumble on or upon
In BrE, the most common way of expressing that you met someone unexpectedly is to say that you "bumped into them".
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.