Yep. You have a leak for sure. Find and fix and you’ll be fine. Check inside all brake calipers and at all fittings. Even the tubing if you still find nothing. The fluid is getting out. Once you fix that, should be golden.
Change both calipers and the brake hoses is my opinion. Once I have to fix something I don't like to go back in a short time later and do the same thing on the other side, they are the same age usually. And brake hoses are cheap and break down over time.