In the rush to leverage social media it's easy to by pass everything and rush headlong into Twitter, Facebook and any number of other cool sounding apps. However, if you are new to on-line social interaction you'd do a lot worse than joining a forum or two.
Long before Twitter was even a public static void main (twinkle in its fathers eye), people were getting all social using forums. Forums are one of the original social media platforms and a great way of easing your way into the world of chatting with strangers, sharing ideas and building an on-line reputation.
There are forums covering all areas of business and leisure from metal detecting (tried it once, it's on my list of things to do later) to fixing up old motorbikes (currently doing that) and most other things in between.
Some forums are very friendly and some less so but it's a great way of cutting your teeth so dive in, search for forums related to your area of expertise or interest and give it a go.