Affiliate Marketing Secrets

I’m running this small store locally that sells cult apparel-very modern, very clean and minimalistic. It’s been fairly successful.
Now, since I’m a 16 year old with a style split personality, I’ve been thinking of selling different items as well. Instead of a minimalistic type of apparel these clothes are more bohemian and loose.
My question is, do I open a different store to sell these in as a sister company, or sell them both together? Opening a seperate business would mean the first store’s hold on the niche wouldn’t be compromised. I’m just afraid two stores would be far too confusing.
Help!