Creating a channel is a great way to collaborate with people!
Need to share part of your code but it’s hard to read or weird looking? Make it a snippet! https://get.slack.help/hc/en-us/articles/204145658-Create-a-snippet
Direct messaging (also known as private messaging) is great way to talk to someone one on one! https://get.slack.help/hc/en-us/articles/212281468-Direct-messages-and-group-DMs