How to repair water damage

The answer is generic, given the lack of model-specific information. We need to know your model to better assist you.

The HP 14 series is generally a lower-end to mid-tier laptop, with some models being better than others. Most of them are commonly specced and tend to come off as average at best. If it needs any major nonstandard parts, there's a strong chance (against you) that the repairs could "mechanically total" the laptop :-(. That said, you may still be able to fix it, but don't be surprised if something as silly as a palmrest assembly kills you in terms of cost, and it's not worth replacing said palmrest without a donor. AND if the model is one of the Celeron/eMMC models that is a few years old, you'd be way better off with a midrange i5/512GB-1TB SSD/HD IPS/16GB DIMM or CAMM equipped laptop to replace it given many of the lower tiered Celeron models tend to come specced with a DOA CPU.

Refer to this guide to clean the motherboard: iPhone Liquid Damage Repair --- While this is for an iPhone, the same steps apply to your HP 14. You will also likely need to replace the battery, given that it may have been damaged, but generally, laptops with LD fare better in not requiring a new battery.

IMPORTANT NOTE: Larger spills often do need it so that it will depend on the severity. If there's any corrosion or liquid near the connector, it will probably need one. Depending on the model, an aftermarket battery will cost $70+ or ~$89+ for OEM. Given the high battery cost, you may be better off taking your chances.

If the keyboard has not fared well (and it most likely will not), we need a model to locate the part number. Some are better than others (e.g., my 640 G9 commercial laptop has the integrated keyboard palm rest, but MDM and BIOS passwords make parts plentiful, knocking the price down several notches; the consumer models do not benefit from this price differential 95% of the time. You need to buy a unit with a major EOL fault, but it has a working keyboard to get the price breaks we get on the used commercial PCs. However, you get to discard the laptop's remains. I've done this for EliteBook and Latitude parts before, but I know how to extend the lifespan of the parts unit such that the waste is minimal; it's generally something like a beaten-up chassis or damaged palmrest which is bent such that I can't readily reuse it anyway.