What do I do if my laptop freezes?

Hello! I been having an issue lately with my laptop, it's pretty old, it's an Asus from like I think 2014. It always been working good but now it's a bit of a problem.

It is more likely to freeze with I'm listening to YouTube and playing a game like Minecraft.

My laptop doesn't have a battery so I use it with the charger to make it work, I think the issue might be because it's overheating or something... 

I need to buy myself a new laptop because I'm going to start art collage and need to use programs such as blender, and I'm pretty sure that will kill my laptop.

I asked a friend and he said it might need cleaning and a new battery, I suppose that's true, but I'm a bit paranoid that could be another problem and maybe something in the inside.

Any ideas?

Thank you for listening :3