Laptop, FL Studio and an audio interface, the Focusright Scarlett 2i2 is a good entry level audio interface, you need the interface for low latemcy. Latency is how long it takes from pressing a key on a midi controller to the software picking it up. You want as low a latency as possible, without it messing up the buffers causing buffer underruns. You have to find the sweet spot for your setup.
You will also need monitors. The KRK Roxkit 5,s are a good start point. Dont want to spend too much at first, making music isnt for everybody and it can get very expenive, very quickly.