Try getting a group together.  I haven't had this problem, but I would assume if you have a group of friends training with you, it would be a lot easier to train in very public places. 

Alright well it kind of sucks but nobody else is as interested in it and it would be way to hard to hook up with someone. Parkour is is not a very big sport at all. And what would you think if two 14 year old kids are running through san fransisco jumping over fences and climbing up on rooftops. If its not the people I am worried about, it is the cops! I want to keep my record clean...

Ya well I am only 14 and just starting out, it seems like that is a big group of really good guys.

And they are a group of really good guys. If it were me, and I had the opportunity to practice/train with a group of really good/experienced guys, I'd take it.

Otherwise, it sounds to me like what you're saying is, "I don't feel comfortable training in public, but it's not a good idea to train at night, and I don't feel comfortable training with an established group, but there's no one else around to train with." If all of this is true, maybe you should just give up and quit parkour now. I mean, it's really too hard, right?

Okay okay, I'm kidding. But the point is, it's unlikely that you'll find the ideal training situation ever. So do the best you can with what you have to work with. I used to feel silly training in public too, when I first started out. In a lot of ways I still do! I worked hard to find a group and that is moving along slowly, but surely. But to me parkour is important enough that it's worth the difficulties that come with training alone, or trying to get a group organized. After all, feeling silly training in public is just another obstacle, right?

I suspect, although I'm not familiar at all with the scene in SF, that if you joined and asked those guys for help with training, they'd be pretty friendly and supportive. You don't lose anything by trying, do you?

As a side note, I don't think you should be monkeying around on rooftops at all, but that's just me. I'm kind of a "den mother" type.

In any case, I hope you come up with a workable solution for your dilemma soon!

Good luck!

Ok well I am not from San Fransisco. And I understand that you are just starting. But I met a bunch of the SFPK guys, and BELIEVE ME, they are there if you need them. I had only just met a few of them and they were giving me tips on my kong vaults, and my rail-to-rail precision jumps. They are incredibly friendly, and they will help you.

As to the parents thing, the best way to do it is to just tell them what you are doing. I had the same problem, where I didn't think my parents would be too happy about me running around and jumping on stuff. But they didn't seem to mind after a while, and I showed them videos and stuff and told them how I'm being safe. Also, for safety purposes, even if you lie and say you are biking, TELL THEM WHERE YOU ARE GOING!!! If you get hurt, and they don't know where you are, they'll be a lot more pissed off than if you got found pretty quick and prevented more serious consequences. And back to the overprotective thing (I know I'm jumping around quite a bit), ask the San Fransisco Parkour guys to talk to your parents. They are all mature people, some of whom are adults. I'm sure they will be able to get your parents to let you off the leash and go train.

And to the first thing, getting embarrassed in public, just don't think about the people watching you. Focus on the task at hand. Just today I jumped on a shed that was already occupied by a couple people. At first I wasn't gonna do it, but then I figured "What's the worst that could happen?" I'll embarrass myself and walk away, that's the worst. I knew I could jump on the shed, so I knew I wouldn't get hurt. And what did happen? I jumped up, jumped down, and they asked where I had come from. So I said the other side of the shed. That was it. I kept walking. Also don't let screwing up in public get you down. People might laugh, but probably not. They don't know what you're doing (for the most part), so they won't really know if you screwed it up, and if they did they'd prolly help you out. I know I would if I saw someone trying Parkour in my area.

Unless you faceplant. Then you look stupid no matter what sport or activity you're doing. 

Whenever I am out in public, and I become embarrassed because of what people might think, I just say to myself, "I am a traceur and this is what I do." So then I go and do it even sometimes doing it better when they watch just to prove to them that I am serious. Just say it next time, " I am a traceur, and this is what I do".

Here's my solution:  Ignore them ["them" being others, the public, etc.].

I used to be very conscientious about what others would think about me jumping around on stuff, vaulting over things, etc.  But then I realized:  Chances are, I'll never see these strangers ever again.  So why should I care if they think it's weird for me to run around vaulting things?.  That's why the quote in my signature block is what it is:

I realized that I was literally losing focus on the flow of movement every time I was worrying about if someone was watching, etc.  So I consciously decided to simply ignore the fact that some people might think what I was doing was odd.

And if you're worried about what people you do know might think, just think about this:  "Yeah, I might not be that great right now, but I will see these people again and when I do, I'll be even better than I am now and they'll get to see me improve so much!

Just remember: worrying, or not even to the point of worrying but just even thinking, about what others might think of you doing parkour, in my opinion, instantly breaks the focus you have on mastering your own movement, which is bad.  So just ignore it.  Don't care.  Forget them.  Then, you will be free to move as you wish....