Scared of doing too much...

Do you guys find that once you're lucid you're a bit sceptical to try anything drastic in fear of losing the lucidity? This might be because I'm new to this, and not yet experienced, but i found that when i was lucid i just calmly walked around and took everything in rather than trying all this weird and funky stuff.

I did, at one point, attempt to fly, but when it kind've ended in a swan dive into the ground and my dream fading.

Will i gain more confidence as i have more lucid dreams or is this a mental block?

you will definately gain more confidence as you have more lucid dreams, but it is important to always test yourself. Anything that you can't do in a lucid is a mental block, because anything is possible. I am by no means in full control in most of my lucids and I still have trouble flying every now and then, but I know that these are just mental blocks which I have to overcome.
As far as just staying calm, I also enjoy walking around in my lucids, staying calm and enjoying the suroundings, but I think is is important to push yourself and your mind to try new things. Waking up from a lucid sucks, but it makes you look forward to the next one even more.

Silverwing, I agree with $MASTA C$!

I know when I first become lucid, I too would have to fight that initial rush of adrenalin when trying something new. I do this by telling myself to calm down, breathing naturally (or a little slower) and by first "grounding" myself in the dream (i.e., make it as lucid as it can be) instead of immediately racing to do something before I lose lucidity.

One of the tricks I use to "ground" myself is to "touch" things. By touching.. I mean really "feeling" them. Get into how they feel.. are they hot, cold, smooth, rough, etc. (this also increases the vividness of the dream along with helping me remain in it longer).

Also, there is no "try" when you're lucid.. only "do". You must KNOW that there is nothing you can't have nor perform while in your dream.

Just remember that "the deeper the level of lucidity.. the better your lucid experience should be".