It is not illegal to pay someone to go on a date with you. As long as you dont engage in any sexual behavior, it will be fine.
Is it illegal to pay for companionship?
Prostitution is the payment for sex; solicitation is arranging for paid sex. Now the hard part, technically an escort/sugar baby who is paid for their companionship is not prostitution--even if the sex occurs AFTER the completion of the companionship (that is sex wholly free and voluntary).
Should a man pay for a first date?
Fast forward to 2020. Despite the persisting gender pay gap, women can make enough money to spend on dates. According to a Refinery29 poll of 656 Millennial women, 59 percent agreed that a man should always offer to pay for the first date, while 48 percent said they would allow their date pay for them if offered.