This may sound like a silly question... I know warding for map awareness is a good thing to do. However, I usually play bot games & don't see people ward there. What exactly happens? does an alert show up on the mini map when an enemy champ walks by a ward? I know I could probably create a custom game or try warding in a bot game, but not many ganks to test it out.

No question is a silly question.

Anyways, there is no alert indications when a enemy walks by a ward. They simply just become revealed in the area where the ward reveals. Regular wards reveal everything except bushes if they are placed outside of them or stealth champions. Vision wards reveal everything even stealth champions, except the bushes if they are placed outside of them

No alert pops up, you just have to pay more attention to the mini map. When an enemy walks by a ward you can see them there if you change your camera to look there, or the simpler way, their champion icon will appear on the mini map just like an allied champion would.

The ward dispels the fog of war in a small area around it. So if you have the whole map warded but never bother to check your minimap, your wards are all wasted.

And there is no point in buying wards in bot games as bots lack the brains to leave their lane and gank until a turret is dropped, at which point they will all start roaming seemingly randomly. Bots also do not gank cleverly like players would.

I actually ward in intermediate bot matches but there is no point in doing it for beginner bots. I always chuckle when I see people buying sightstones in beginner co-op games .

There will be no alert, but you will be able to see the enemy icon on the map, something you wouldn't without one.

That's why it is very important to keep an eye on the minimap to make sure you know where your enemies are, and then warn your teammates if they are in danger.

That's not nice.
I could say

"I always ward in ranked, but there is no point in doing it for normals. I always chuckle when I see people buying sightstones normal games "

Is that nice? No.
You are implying that people who play intermediate are better than people who play beginners, (same way on my example I am implying people who play ranked are better than people who play normals, and both are not nice).

People are free to play however they want in whatever game mode they want, as long as they are not making the game unpleasant to other players.

and FYI, even beginner bots roam, gank and walk through jungle, after a tower is down, so it is not useless to have a sightstone.

Haha, I would be one of those people!

It is quite silly given the general lack of intelligence bots possess, but nonetheless it's good practice to just get into the habit of buying and using them.

But yeah, there are absolutely no alerts the game gives you if an enemy walks by your ward. It all comes down to you and your team's map awareness.