The first place where people ask for help about Selenium is the Official User Group. Here, you'll find that most of the time, someone already found the problem you are facing right now, and usually reached the solution for which you are looking.
Note: Please make sure to search the group before asking for something. Your question likely won't get answered if it was previously answered in another discussion!
All of the methods below are mirrored so you can pick your favourite below.
The best place to ask for help is the user group (because they also keep the information accessible for others to read in the future). However, if you have a very important (or too simple) issue that needs a solution ASAP, you can always enter the IRC chat room. You might just find someone ready to help on #selenium at Libera Chat (irc.libera.chat). There is more info about IRC on Wikipedia.
If you would prefer to use Matrix then you can do that by joining the Selenium HQ Space Selenium channel.
Selenium's Bug Tracker can be used to log new bugs, check the status of an existing one or as inspiration to help make Selenium better.
Selenium is a diverse project and many commercial services have sprouted up to support it, some of which offer professional support for using and developing with Selenium.
First, please check out our Sponsors for your needs.
You can also learn more about the Selenium Ecosystem to see if there is a company that might be able to help you out.
Certification and Training
Learning how to use Selenium effectively can be a taxing task. There are various companies who offer Selenium training.
There is no officially recognised Selenium certification available, and the project developers strongly believe that certification is of no real benefit to individuals or the industry. We have not authorized anyone to offer "official" Selenium certification and anyone who claims to offer it is misusing the Selenium project's trademark.