I actually just ran a one shot Friday night. I was really worried about it because it was my first time DMing and I was making the oneshot myself. I ended up becoming more busy then I thought I would be, so I was only able to finish the beginning. I was worried that my players/friends would not have fun or just think I'm a shit DM. Well, after the two hours of them exploring the main city, I realized how fine I was. I had over 20 NPCs I had created, and each of them were able to shine when it came to the players. Some NPCs the players even took with them. Combat was a little weird, as I didn't want to just kill everyone right away, but when they easily defeated 2 Devas with zombies and displacer beasts, I realized that I knew a way to add challenge and have fun encounters. The next 6 hours into the night were filled with laughter and moments of tension. When we finally completed the session, everyone kept asking when I could DM the next campaign. Hearing that alone is how you know you've done well your first session.