Uhhhm. I wouldn't know about blogs, but if you have at least 50 posts in forum threads then you'll become a genin and will be able to create your own Bio^^
Thanks Do I Join A Village Before I Make My Bio
I can't say, better ask someone who knows, for example Lawliet or Caliburn, they're both global mods, but I think it's ok to ask them this.
I'll save Cali the trouble of being pestered u.u
50 posts in the forums gets you to Genin, you don't have to join a village before you make your bio but you can try if you want. Some villages accept people who don't rp but some don't so it's better to make a bio before trying to join.