You go to the characters tab on the site and click on Create new character. Read the rules to check your character fits with them and click Continue. Then you type in your character's name and their biography, or bio for short. It should include their name, meaning (if needed), age, parents, siblings, mate, cubs, likes, dislikes and personality as a minimum. Then you write a history (still in the description box). This needs to include quite a bit of detail as their life as a cub until adult, unless they die at a young age. Finally, credit whoever made the headshot and the full body base (even if it is yourself) and write how your character is related to the Lion King. That is very important! Next you upload a picture of their head - just their head - and next their full body picture. This has to include all their paws and their tail. Then you select whether your character is realistic or not, so whether it would fit in the Lion King Universe with their colours. Then it is who is allowed to use your character. If just you want to use it then select Private. If you want to allow only a few people to use your character choose Protected and if you a fine with anyone using your character click Public. Animal/human type and Gender are pretty obvious, as is the main colour. Then you can send your character. As it has to be moderated, it won't appear straight away, but the moderators here on the site are really good and it should appear soon!
Hope this helps!