CuriosityKilledTheCat

Hiring a guy to try or learn something new is a great idea. Like @DWnyc mentions, it is a good way to try things without the pressure or reactions you might get from a guy you've met on an app or somewhere.
Let the guy you're hiring know what you want to try and learn, and let him know you're being truthful (so he knows it's not just a "first time fantasy" ploy, though he'll figure that out soon enough).
I'm curious though why you say you are feeling pressure to fuck. Don't do something just because you think everyone is doing it or it's expected. There are plenty of things to do besides fucking, and lots of guys are just fine with that.
But then again, fucking can be really awesome, and it sounds like you have a guy in mind who you'd like to try it with. You can do it.
I suggest you post in the Deli forum asking for recommendations for someone to show you the ropes, and be sure to say where you are located. I'm sure you'll be able to get some recommendations.

If you’re looking to engage in a new aspect of sexual interaction, you’re more likely to find a hired partner with the complimentary skill set for what you want to experience than a rando from apps. You’re not looking for anything that isn’t on most available “menus” but providers are just more likely to have had recent experiences with first-timers. Good luck!! 
 

If you explain this to a provider when inquiring about an appointment and they’re willing to take you on, I think they can be helpful. Some may think you’re role playing and trying to act innocent / “first time fantasy” etc but so what (unless they assume part of your fantasy is going from zero to a hundred in a few mins, the only thing I’d advise you to be wary of).
So I’d advise you to go with someone you like based on their profile and take it from there. Ask lots of questions in the session, in a way that might be uncomfortable in a non provider environment. 
Its actually a good way to cross some thresholds without the pressure of “real people” and their reactions. You may even want to try bottoming in a safe environment to test your assumption. 
Good luck. 

Good evening everyone -
    I am a decent looking 40-something in athletic shape.  I've been with guys before (making out, oral, frot, j/o), but never fucked.  To be honest, I've never had the urge to.  However, I feel some kind of pressure to do so.  There's a guy I like, and I know he's a bottom.  I don't know "how" to top, and I don't think I could ever be a bottom.  I was hoping to perhaps hire someone to "teach" me this skill of topping and was looking for guidance or suggestions with this.  Thanks!
- J

Good evening everyone -
    I am a decent looking 40-something in athletic shape.  I've been with guys before (making out, oral, frot, j/o), but never fucked.  To be honest, I've never had the urge to.  However, I feel some kind of pressure to do so.  There's a guy I like, and I know he's a bottom.  I don't know "how" to top, and I don't think I could ever be a bottom.  I was hoping to perhaps hire someone to "teach" me this skill of topping and was looking for guidance or suggestions with this.  Thanks!
- J