Visa from hk to guangzhou

Hi, I want to plan a weekend to Guangzhou from Hong Kong and wondering how that works since I have a Dutch passport. I just read that it's possible to take a train from Hunghom straight to Guangzhou after getting a visa. But are there customs at Hunghom to scan my passport to register that I exit Hong Kong and enter China-Guangzhou? Just never seen customs at a train station.