Will a crime caution effect me getting into university?

[Anna]

2 Years ago (I was 13) I was with 2 girls. This 2 girls always bullied me if I did not do what they asked, and had a lot of influence over other girls at the school. I tried to get away from them many times but I was left so badly bullied I didn't eat for 4 days and didn't bother going school. So when they asked me to go to this village with them one day, I went. The day wasn't too bad, I didn't say much, but they didn't either. Until we went to a shop and they told me to steal a bottle of wine. I didn't know what to do and I was so scared, I didn't really think and nobody was looking, and I didn't think of the consequences of getting caught, I thought of the consequences of not doing what they said. I ran and didn't get caught, until 2 hours later when a police woman saw my 'friend' who matched the description given. I owned up and I apologized to the shop keeper, and he was very nice and let me off with a caution.
I am now 15, and I have got away from them girls after a lot of hard work, and luckily I'm not in any of their classes or any one they know classes anymore. I go to a really good school and I get all A*, and everyone has really high hopes for me at GCSE. I have learn't from my mistakes, and actually that is one of the main reasons why I tried so hard at school and got where I am now.
I got a lot of bullying for it, one time I even got repeatedly hit by a boy because I didn't want to talk about it, but that's over now.
All I'm wondering, is how will this effect me in the future? Will I be able to get into sixth form/university? and what about a job?
I'm mainly worried about sixth form and university at the moment, I can worry in the future about a job.
It was only a caution, but will sixth forms look into that? I know my sixth form looks at people who have posted stuff about it on Twitter. And what about university? Like maybe Oxford or Cambridge?
Also if you could answer this:
A guy managed to take a photo of me in the police car, and put it on facebook. He is 2 years older than me and very intimidating. I used to have him as a friend on facebook, but after I saw the comments I got on that photo (they were very bad) I deleted him. I went back recently to look for the photo, but I couldn't find it. I don't have him as a friend anymore, and there is a possibility that it's still there but I can't view it because he is not my friend. I don't want to ask any of my friends about it, because I think they have finally forgotten about it, and I don't want to ask him or add him as a friend because he really scares me. I was just wondering if the school will find this? or the university? and how this will effect me
Thank you for helping me, it really means a lot