I think you mean Trademark, not Copyright.You have just started your business and you want to put a copyright mark on that.
I think you should first check out that someone else have not used your symbol or have the copyrights of your symbol or logo, because if someone else have the copyrights for your symbol then you have to change it.
Trademarks are for logos, brand names, etc. Copyrights are for works of art, such as t-shirt designs.
When claiming the rights to a trademark, the ™ symbol can be used at any time. The ® symbol can only be used when the mark is officially registered with the US Trademark Office.One more thing if you have not registered the symbol then you can not put a copyright mark on your label.
When claiming the rights to a copyright, the © symbol can be used at any time.