You need to check your city code for regulations. If you live strictly in a residential area, your chances of opening a thrift store in your home are very slim.
Once you check your city codes and if you find out you can, then check with the Small Business Adaministration about starting a small business. There are sometimes loans and/or grants for women. They can also give advice on developing a business plan, budgeting, taxes, etc. I don't know where you live but in some places there is information available through the Chamber of Commerce.
If you find out you cannot run the store through your home, then you need to start looking for locations. Here is a link to the Google page on how to open a thrift store:
how to open a thrift store - Google Search