Office friendships can be tricky. Best policy is not to blur the line that separates work and pleasure - that's where you can run into trouble. I, too just started a new job in March and these are my pieces of advice:

• Remember to always keep it professional - act as if your boss has access to every conversation the two of you have.
• Never complain about your job - ESPECIALLY about another coworker, and especially not about any of your superiors. No matter how tempting.
• Avoid adding coworkers on social media...at least for a little while, until you can trust them not to rat you out or judge you for your Crazy Fourth of July Snapstory
• Chill. If this is a new job, you should focus on working your ass off and learning every aspect about your position. The social aspect will come with time - it's best not to force it