Yeah, just Create New Server and there should be a tab where you can add bots and control their difficulty.
For some "zombie" fun, set it so there are at least 20 bots on the enemy team against you, but they can only use knives. Make sure the difficulty is on Expert. Very intense sometimes, when you're trying to climb crates before the horde gets you.
Overall Counter-Strike is a great game (most popular online shooter in history) but it's really not my cup of tea. I played it a lot when I was like 14, but now I realize it's not a good game for me.
Like most games of its type, it is difficult to enjoy without playing multiplayer.