hi folks. I realize this may be a bit of a sketchy post, but alas.

I'm trying to install avp on a macbook pro with portingkit. I'm using the offline installer file. every time I try to install, I get stuck on "installing winetrick d3dx9_36".

I have left the installer running overnight, to no avail. I have done considerable searching through various forums (including this one) to find a resolution, but none have appeared. the closest I've found has been the topic "avp on wine" but that did not seem to apply to what was going on for me. I am not a well-versed computer user, so a lot of things admittedly go over my head. does anyone have any insight? thanks in advance.

A MacBook Pro running what? It's getting stuck before running the GOG installer, e.g. in the PortingKit side. Assuming it's not the OS.

I'm running el capitan 10.11.6.

Good, so not Catalina. The winetricks script might be outdated. I now remember why PortingKit pisses me off. I can't see the source and I don't know where the formulas live. You can try updating winetricks either through PortingKit if it lets you or manually by downloading the latest version & overwriting the PortingKit version.
Another option is Gcenx's unofficial Wineskin, look under releases. With that you would manually need to do the install plus any overrides/configuration.

thanks much. I'll report back.