First of all, don't go in May; the weather is horrible. Best times to go are in April or October, immediately after and before the tourist seasons.
If you are going to exchange dollars for reais, I don't suggest the cambios at the airport, or the ATMs, as you will get a really bad exchange rate. Look for a cambio in a mall instead.
Private 55 is one place to find ladies, but I took a different route. It's very easy to pique girls interest from all over SC. If you go to Joinville for interest, you may get ladies offering to see you all the way from from Blumenau. A lot of times the women, especially the younger ones, feel trapped in some of the smaller towns, and love to go somewhere else to find something to do. Of course, they will expect you to pay for their transportation, but you don't have to front them any money, you can always send a car from your own Uber account to pick them up. Uber is very cheap in Brazil... a multi hour drive won't set you back by very much.
You can always look for local girls, but they come and go quickly. Sometimes they just want to get into sex work to pay off college loans, then quit when they are done. Other times they may visiting and working in a resort temporarily, and then go back to their home city suddenly without notice. It can be hard to tell from the ads, who is available in the moment, and who is not.
Price wise, you will probably be looking at somewhere betwen 500 and 800 reais, and they may be willing to spend much more than an hour with you. Current conversion to USD is to divide by 5, approximately Also, in SC for some reason most people don't seem to notice if a guy is spending time with a girl 20 years younger than him, or a couple who do not speak much of the same language. It might be because they get so many tourists in such a sparsely populated state that they don't care, simply are not paying attention, or are used to it.
Also, if you have Wise, you can ask them if they will let you pay to their Pix account, rather than giving them cash. This will let you finance, albeit for a small fee, and not have to worry about carrying around large amounts of cash.
Also, if a girl tells you she is some Brazilian model or influencer, then I would not recommend seeing her. She will be unreliable, with an attitude problem, and quote you something outrageous like 2,000 reais for a visit. Look for the ones who respond consistently and in a timely manner.
Also, keep in mind that if you aren't visiting in the tourist season, some places will be closed, and others will have limited hours. But, if you go during their summer, everything will be way more expensive, more crowded, and it will be hot outside.
Also, with the younger crowd, they are actually more likely to know some English rather than Spanish. Still bring a translator app if you don't know Portuguese. Also ask about services ahead of time, and verify they aren't trans.
Those are my tips!