Hi, I'm new too but I have understood a few things
You should perhaps download and install the 4Gb mod which allows you to use 4gigs of ram instead of only 2 (if you have more of 2)
I will copy paste the post that helped me:
"The 4GB patch is extremely useful in providing better stability. Here's a simple one you can download and simply apply to the SH3.exe:
https://ntcore.com/?page_id=371
You may have to provide permissions such as unchecking read only in properties of SH3.exe"
it basically improves stability of the game, and maybe it's the cause of the crashes?
Which kind of alert-box does your pc give when you crash?
Try it out and then tell me if it works ^^