A laptop won't get you far, but you can mine with some desktop apps that have the option of mining only when there's no usage of your laptop(in idle mode).

Here's a list of such applications: https://telegra.ph/Cryptocurrency-Mining-Software-List-03-08

Even with modern/expensive laptops, it's not worth mining with them unless you mine something you think will rise up in the future.

If you're considering what to buy yet, and want to mine, go with a desktop configuration for the same buck.