Beginner's second PCB circuit design: AC to DC
Per IPC spec you need creepage and clearance, even if your not using this in a product (and getting it tested at an ETL).


Source: http://www.ni.com/white-paper/2871/en/

That means if you have AC mains running into your board, you need at least 1.6mm around the conductors that carry that voltage (meaning the hot and neutral lines) and any other conductor. This is for pollution degree 1 which for you means no dirt (stuff that could lower the conductivity of the PCB).

It's generally a good idea to place a large gap between AC and DC sides of the board for good measure. If this is a product it needs to be double insulated or made inaccessible to someone who would service it.