No window appeared after I clicked "play" the game. Can only force quit it...
I heard about installing wineskin can solve this problem and I tried this before, but somehow, the fan roared after I played the wineskin BG2 complete, so I degraded my mac to mojave considering it might be the 32-bit issue, still it didn't work on Mojave. Any solution to this?

Problem solved. What you need: Mac Mojave or lower version; the BG2 complete (classic) that you acquired through serial key.

What you need to do: Download BG2 complete, and then find this app icon in your Application in Finder, and Right click BG2 complete => Show package contents => Click "Contents" => Click "Resources" => Click "Game" => Right click "Baldur's Gate 2" => Show package contents => Click "Wineskin" => Set screen options => Cancel Check "Auto Detect CPU Info for Direct3D" => Done => Quit.

Now launch this game in Application again, and you can play it now.

This is a way I know that you can play BG1&2 vanilla in Mac while making sure your fan and CPU temperature work fine.

Thanks for the solution.

I had a permission problem on run because of the trustlevel of the distributor.
I had to set the permission for the game on first run.

I could not start Wineskin before the permission of the main game application had been set.

I used also a solution for Baldurs Gate 1 here:
https://www.gog.com/forum/baldurs_gate_series/bg1_wont_start_on_mac/post3