First time any suggestions for what Should I do

[artyboy]

Okay there are somethings you can do before hand such as;

Only eat soft foods like yoghurt, smoothies etc for a few days before.

Go for a poo.

Get a douche rocket (it's what I got)

Then use it with warm (not hot) water and basically fill for backside up and jump up and down a couple of times and push it out of you into the loo and repeat till the water is clear.
(you don't have to do that but if I was you I would).

Before he enters you use fingerings or anal toys to help get you ready for sex.

Number one thing is to relax and have fun and take your time.