Taper week ahead of first HIM

I wouldn't worry too much about doing a brick. Do one early and the other later, or split to two separate days, don't overdo it though as the delayed onset soreness can get you if your not use to it.  Since you can always walk parts of the run during the race, see if you can go the distance on the bike, keep the pace easy, play with the nutrition on the ride as that's important, ~250-300 cal per hour and hydrate as needed with the weather.  Just keep moving this week decreasing volume.

Not sure how much training you did up to this point.  But for my 1st HIM I had a bike crash in an Oly 6 weeks before that lost some skin on and kept me out of the pool for a month. I focused on running and riding once the deep knee wound allowed after about a week.  Then just under 2 weeks before the race wife and I developed a nasty chest infections, kids were little then and we seemed to catch everything from them!  I had a business trip the week of the race and was still recovering from the infection and got moving a bit again.  Race day came around I had a decent time, definitely slower than I wanted but I did it.