Although RPGs are traditionally played in-person, in today's busy world, it's becoming more and more common to play virtually. This page will introduce you to multiple platforms and tools for playing online.
The website Cloud 9 Tabletop has an in-depth article on playing Dungeons & Dragons online. It'll help you decide what you want out of a game as well as direct you to places to find other players.
D&D Beyond is an official partner of Wizards of the Coast, the creator of Dungeons & Dragons. Although it doesn't offer a platform for playing live, it offers a lot of good tools for learning the rules and keeping track of your character. Start out building a character, and then use the generated character sheet to work your way through combat. If you're not ready to make a character, D&D Beyond offers pre-made character sheets.
Roll20 is a site that houses rules and adventures, and it's especially useful for playing remotely since it offers a virtual tabletop where players can see a shared map, roll digital dice, and use mics and video cameras to communicate. It also offers versions for Android and iPad.
"Astral makes creating characters and playing your favorite tabletop games easy." Astral offers a free version and a pro version. Keep track of your character and their actions, roll dice, chat with your group, and create maps.
"Tableplop is an online, browser based virtual tabletop for roleplaying games where you can share an encounter, roll dice, track initiative, see character stats and chat. Connect on your computer, your phone or your tablet and explore a world together, but remote.
"Game masters, roll up your sleeves because Tableplop has all the tools to build incredible scenes using built in tokens, your own uploaded art, drawing tools and Fog of War."
Skype, Zoom, Google Hangouts, Facebook, etc.
The easiest way to play online is to use software you're already familiar with. Any video-conferencing program that will let you hear your friends will work! Video cameras are optional but helpful. Although it's nice to have virtual maps, it not necessary, but if the DM wants to get creative, they can always share their screen.