You're not doing anything wrong. Unfortunately some categories are full of idiot sellers, and logo design happens to be one that people with no skills think they can do.
In buyer requests you only get to see requests in your gig category so I'd recommend having a few different gigs that can go in different categories, then you'll see more requests and hopefully not so many of them will be sellers advertising their work without realising that buyers do not see the buyer request section, except for their own requests.
What buyer requests sorely needs is a report button.
Anyway, more gigs. And good luck. I would also remove this line from your profile "but I still consider myself a beginner". It might be honest but no-one's going to hire a beginner when they can hire a 'professional' for the same price.