Tax ID for stained glass products hobby
If you are selling your glass products then you are conducting a business. Every business (with a few exceptions, such as single member LLC with no employees) is required to obtain a federal tax id (also called Employer Identification Number).
If you would be selling any of the stained glass products to buyers in your state, you would indeed require a state sales/use tax id to collect sales tax from those buyers, unless your state and local jurisdiction do not have sales tax.
There really is no specific amount of sales required or allowed before you would require this permit, although some jurisdictions do allow small amounts of sales being done with no need to report.