What would be best?

I am planning to buy a new hp laptop with a Intel pentimum 4gb ram 500gb HDD.
i have an old laptop that I will sell, so wich one of these should I buy?
a better cpu
more ram
an ssd.

Firstly, check that the components are upgradeable. Its not common but I know that the CPU and RAM on my laptop are soldered on; I wouldn't want to try and upgrade them.
To answer fairly I would need to know the exact CPU and more importantly what you intend to do with the laptop. If you just want to read emails save your money and buy some beer or something.

Yes, they are upgradeable
i plan to play flash games/minecraft.
2.16ghz

4GB should be plenty of ram for Minecraft and any flash game, I would be considering an upgrade to the CPU. Does the laptop have dedicated graphics?

If it were 2004, that might have been a good laptop. But today you really don't want to buy a Pentium.

I suggest you look for an i5 CPU and 6 to 8GB of RAM. The SSD I would buy aftermarket and replace the HDD which makes a nice external disk in a little caddy. Laptops with SSDs are very expensive and you can get a 240GB SSD for around $100.