Starting Pet Boutique

Hi, I'm new here looking for information. My wife expressed her desire to start a business and our love for animals led us to a pet boutique. We plan to initially start small scale online with homemade treats, leashes, and collars. Neither of us have business background but my wife has worked retail for 10 years. We have never done online business either. Do i need a business license for online sales or just a physical store? Also whats are some pprotections or precautions i need to take with making leashes and collars, ( eventually i want to add beds and cat trees). In the future we would like to scale to a retail store. Does anybody in the business have any information i would greatly appreciate your help? :)