I think I had one

I stayed up kind of late last night researching lucid dreams, and I went to bed at around 2 or so. I have never practiced the lucid dream techniques or even kept a dream journal, but when I "woke up" in my dream my room was very dark and I was very dizzy and kept stumbling. The feeling of being in my physical body wasn't very strong, but it was there. It didn't feel like reality, but I knew that something wasn't right. I remember trying to figure out where I was and what was happening. I also remember I had checked in some way to tell if I was dreaming or not. What I did do to tell was start spinning, because I had remembered reading that spinning would prolong your lucid dream. It kind of felt like I was spinning above the ground. This worked to an extent- the light got a bit brighter, but then it would become dark again. My lucid dream was relatively long, though. It all just seems disconnected now. It is hard to remember the whole dream, but it was certainly a very strange feeling. I felt like my eyes were open when I was dreaming! I also had three or four false awakenings. I opened my eyes in the dream, but realized I was still dreaming. I was able to think pretty clearly at this point. Right after I realized I was still dreaming, I went back to the dream. This happened repeatedly. After the stumbling around my room part, the dream just got more and more random and disconnected to the point of being just a regular dream.

Can someone please tell me if I had a lucid dream and explain what happened and what I can do to improve my chances of having a more vivid lucid dream?

I think you did had an LD. But basically it is when you know you are dreaming, and you did know right? so it was an LD :D

For dream vividness, try to look at your hands and make out every detail, or rub your hands together. This has helped me increase the clarity in my dreams.

I hope this helps.

I don't think you have to do much to increase the vividness & clarity of your dreams - every night is a different story. I would start a dream journal, a very detail-oriented one, if you haven't already, but aside from that just keep your motivation high for becoming lucid - you're bound to have some amazing experiences.