First get a dildo and try it to see how it feels.
Also, please don't tell escorts you haven't bottomed in 20 years, this would be your first time with a man, you're a virgin, etc. 99% of the time someone tells them that it's a waste of time because the "potential client" is only interested in phone sex, sexting, fantasy, etc. and he'll never make plans/show up.
Just select a few of the MANY choices you have in town and tell him you're not very sexually experienced and you want him to be patient with you but PLEASE don't use the wording I described in the previous sentence because many guys won't even bother to reply to you.