You need to be specific on some aspects.
1| You need to specify the make and model of your PSU. It's considered the heart of the system so if and when it has a heart attack it can be fatatl to the system.
2| You didn't specify the budget of your upgrades nor did you state your location since the cost of parts will vary from country to country and sometimes from Microcenter to Microcenter.
3| If you plan on running a discrete GPU then you can think of changing your PSU first and then jump onto a GPU.
4| If you plan on boosting the onboard GPU on your APU then you should aim for no less than 2400MHz ram kits and in this day and age you'll be best served by going for a 2x8GB 2400MHz DDR3 kit.
5| Stock cooler isn't a good cooler in terms of noise so I'd drop some money onto that as well. Since your board doesn't have any heatsinks around the socket and power delivery areas, you should look at top don cooler like the
Be Quit! Dark Rock Top Flow to help prolong the lifespan of your board.
6| I would also invest on the case if the one you're on isn't up to par. I'd side with a Coolermaster N200.