Mostly its no more technical than a red or even a blue at a trail center, you juat ride it much quicker as its on a propper hillside. Theyd be graded as Black in the UK but thats mostly down to the speed and jumps which are optional.
You wont struggle, its not like for example Stainburn where the features are more do-or-die, you’ll just ride at your own pace or arround stuff.
150mm will be plenty, its all I had. Any DH bikes will leave you for dust in the technical bits, but theres an equall ammount of pedally bits where I wanted less!
If you’re worried then maybe do a few UK uplift days to get into the swing of things. The thing that surprised me most was I actually didn’t like 100% uplifts*! I much prefer longer decents and time on the bike.
*on the DH week, enduro week was my favourite weeks riding ever.