Both fixed riding and clipless riding have a learning curve. If you've never ridden fixed before, it's gonna be a real shock to your system when your whole technique suddenly has to shift AND your feet are locked into the pedals while you're doing so.

I'd recommend picking up a super cheap set of platform pedals (your LBS should have some for 5 or 10 bucks) for the first week or so of fixie riding, just so you can get used to the constant pedaling you're going to have to do. I'd say 50 miles of getting used to fixed is probably enough. Then feel free to go clipless.

But for your own sake, don't try any tricks in the beginning. If you think you can trackstand, and you're also just getting used to clipless, you will be ****ed big time. Tipping over at 0mph with your feet locked into the pedals is no fun.

Good luck.