I really need to know what the absolute best portrait lens is for my Canon 90D because I've spent three days staring at charts and I'm more confused than when I started. I have to shoot my best friends engagement photos at a park here in Portland next month and I really want that professional look but my kit lens is just not doing it.

I did some digging and everyone keeps saying to get the Sigma 50mm f1.4 Art series but then I read a bunch of threads saying the autofocus on the 90D is super finicky with third party lenses and you have to get a dock to calibrate it? That sounds like a total nightmare and I dont have the patience for that. Then I looked at the Canon 85mm f1.8 which is way cheaper and in my $500-600 budget but people say on a crop sensor its basically a 135mm and I'll be standing a mile away from my subjects just to get a waist-up shot.

I just want something that gives me that creamy bokeh background without me having to shout directions from across the street or spend $2000 on a lens that weighs five pounds. Is there a middle ground I'm missing or should I just risk the Sigma and hope the focus isnt garbage out of the box?