Can my computer run Warcraft 2 Tides of Darkness? I mean i use integrated graphics so i doubt i can run it, so i'm asking here. Also, will gog.com accept visa gift cards for paying to buy games that are downloaded?

Is that a joke question? Unless your computer is from the early 1990s, it should be able to run Warcraft 2 just fine, it's not like it has demanding graphics.

I used to play this a lot on a old Pentium 3 PC, and later on a laptop with integrated graphics. I think almost anything capable of displaying video made in the last 25 years will be able to play this smoothly. The GOG version doesn't have remastered graphics or anything, so I think the system requirements are more or less unchanged from the original release.

Warcraft II BNE was literally designed to work on a basic windows compatible integrated graphics card at the time.
You will have NO issue running it on a modern integrated card and yes they do accept prepaid visa's I had no issues using one I got for Christmas.

There is a remaster of War 3, not 2. I don't know what your specs are, but I'm absolutely positive you can run it. You'll have to try the gift card and see if it works. Some do, others don't.

you can play it. the Battlenet edition was patched on gog most recently in 2019: Warcraft II patch 2.02 V4