Can I serve complimentary wine or champagne to customers in my beauty salon? should I have them sign a waiver?

To obtain a meaningful answer, you are going to have to discuss this with an attorney in your area who is familiar with local ordinances. If you are in the City of Fort Myers, the restrictions will be different than if your business is located in Lee County outside of the city limits. It will also depend on whether this is a one-time grand opening party or something that is a regular part of your business. You probably should also check with your liability insurance carrier as to whether they would approve of or provide coverage to you, if an injury resulted from this activity. This is probably not what they would consider to be within the scope of the business activity they are insuring. From a practical standpoint (assuming it is permissible under applicable ordinances), it will be difficult and probably not very welcoming to have people sign waivers as them come in your business. (That's the kind of thing we lawyers would think of and do, which is why we are so beloved by most of the public.) From a legal standpoint, with no slight intended to the personal injury bar, no matter what someone signed, if you didn't take action to prevent over consumption or buzzed/drunk driving (again something that would turn off customers you are trying to attract by your efforts), if someone is injured as a result of consuming alcohol on your premises, a good lawyer (probably even a novice attorney) will find a way to seek liability against you.