This is my wheel house! Let me help you out!
So firstly, I would highly recommend reading your Player’s Handbook (PHB) all the way through to get a feel for the mechanics. I also really recommend 5th Edition if you’re just starting out. It’s the newest and fairly easy to learn, and it’s a lot of fun.
There are a few tough things about finding a group- first, depending on your location it might be tough. A lot of places have officially sanctioned D&D Adventurers Leagues at local game stores that are open to all ages and experiences of players. They will happily teach you how to play. The above linked website should have a league finder that should find what’s close to you. If you’re more rural, this may not be the best option for you sadly.
Secondly, finding someone to DM can also be tough. Everybody wants to play, but not as many people want to DM, and DMing is a supremely daunting task for new players, I would recommend playing a game for awhile before you try running anything on your own.
As for online resources: RPG Game Find is a good place where people post that they are looking for groups in specific areas.
Roll20 is another great resource, that focuses a lot on the online community. This might be the best thing for what you’re looking for.
Worst case option Meetup which can be pretty hit or miss.
Hope this helps! Let me know if you have any other questions!