I own an LLC that I set up for a vending business. However, I didn't pursue it, and now I would like to change it to a mobile eco friendly car wash and also a going out guide/promotions website. Could I do it all under one company?
In general there is no problem in selling multiple services or products from of a single company. Many many companies do that.
You might want to consider:
And last but certainly not least: How about your own energy level? Do you have the resources to start two business areas at the same time, or do you risk starving each business of the attention it needs to succeed?