DIY Powered USB Hub PCB
I would also advise against doing a USB hub if you're not familiar with PCB design. As mentioned in the comments already, you're much better off getting a commercially made USB hub.

PCB design involving high speed busses like USB usually need special consideration when laying out the board (like impedance matching, trace length matching, reducing cross-talk , etc). If you're not careful, you might end up with a hub that only works with USB 1.1, one that's unreliable, or not functional at all.

If you really want to give it a go, find a USB hub chip that fits your requirements using the parametric parts selector of your favourite electronic parts distributor. The datasheet for the chip usually contains a schematic of a reference design that you can use in your design.