If you have come to this page from outside of h2g2, such as Virtual Pets Links you have been mis-led.
This is just one page among thousands of pages on h2g2, and does not cater specifically for children. The h2g2 Pet Adoption Agency, is just a bit of amusement for the mainly adult oriented web site.
Before you can put the picture on your Personal Space (PS), and that's all it is, just a picture, you will need to add an introduction, and change your PS to GuideML, the markup language used here. I suggest you choose another more suitable site from Virtual Pets Links for your age to adopt a pet.
If you have come here from a link within h2g2, you have added an introduction to your PS, and changed it to GuideML please continue and apologies for your inconvenience.