I want to learn browser automate, which program language should I learn?
Selenium with Python or Java. Any language so long as it can use Selenium, really. I'd also highly reccomend a xpath finder add-on for your browser, it helps speed up the process of finding elements a lot when you're writing code.
I dont know about other languages but Python has some pretty impressive modules for browser automation and I use them all the time. You can handle url requests with libraries like urllib, requests etc. Python Selenium is a world of its own. You can do almost every browser task in selenium with windowed or headless mode.