WLED automatically limits the brightness of your project so your power supply doesn't get over-taxed. The default amperage is 850mA, which is a little low for most power supplies.

For some projects, especially battery-powered projects, having the limiter turned on is a good idea. But if you're not getting the brightness you expect, try adjusting this number to match the amperage of your power supply or battery pack.

Turn your project on and give it a minute or two to start broadcasting. Look in your WiFi networks and find WLED-AP - this is a mini WiFi network being broadcast by the microcontroller. Connect to it - the default password is "wled123". An instance of WLED will automatically pop up and you can control your project from anywhere.

If you're putting your lights up in public, it's a good idea to change the AP Mode default password so strangers can't log in and control your lights. This could be a security risk.

AP Mode only broadcasts for a few minutes after you boot up the board so if you don't see the WLED-AP network try rebooting.

There are a couple different apps available to manage your WLED projects. Name and organize your projects, and find them quickly without having to type in a URL. Check the Apple or Android store for downloads. 

My favorite is "WLED Native". It allows you to organize multiple instances and easily switch between devices without having to remember any URLs. 

Under Config / Security & Updates you will find a place to back up your data. It's a good idea to back up your config file as soon as you're happy with the settings. Save it as a .json file on your computer. Now you can prototype and experiment to your heart's content, and if everything breaks, just re-upload this file. Or, if you're doing another build you can use this feature to copy all your settings from one board to another.