Spilled water on Macbook Pro 13 inch, early 2015

You won't know anything until you take it apart, that is the sad truth. In the mean time, keeping it angled with the vent up and the trackpad down will hopefully make any liquid that got in stay away from the motherboard until is evaporates. If any corrosion is happening, you may not notice until an electrical connection is actually disrupted by it.

OK, having wrecked a couple of Macbooks myself because someone spilled liquid into them, I'll tell you what to expect:

First, power it off and remove the battery if you can (but I don't think you can with your model) and prop it up so any liquid can run out. Give it about a day for the liquid to dry.

Or better yet, get it to a repair shop if you can. They'll know how to take it apart and dry it out. Note that it's important to remove the liquid and not dry it in place. A hot-air hair dryer would not help; you could just as well air-dry it yourself. Jets of compressed air that actually blow the water out of the machine would be better.

Otherwise if you have a teeny-tiny phillips-head screwdriver, and the guts to do it, dismantle it yourself and pat everything dry that you can reach. Keep very good track of which screw came from where.

The bad news:

After the liquid dries, the residue remains on the circuit boards. It will almost certainly contain sugars or other corrosive chemicals. These will slowly eat away at the circuitry. So you think you dodged a bullet with the spilled drink, but in about three years you will start to experience unexplained flakiness. I spent about $400 replacing parts in mine before I remembered the mocha someone spilled in it three years prior and realized that I would certainly have to replace the motherboard itself.

The good news:

In your case it was just water, and just a little bit, and not on the motherboard. There's a good chance that you did dodge a bullet. And in any event, you have probably another three years to start saving your pennies for a replacement.