Use freenode irc. Create a room for you and publicize your channel across other bitcoin and altcoin channels. People will come and join and discuss with you. Be cautioned to trade with anyone if you wish to trade directly with the people. Scammers are everywhere.

This is a good read for you.

https://freenode.net/faq.shtml

To publicize your channel, you can post in other altcoin channels. For a list of channels, search bitcointalk for freenode, irc. Also, you can create a subreddit and ask people to subscribe and discuss there.