Yes,it will be. Intel has not made large gains in performance for the past few generations.
16GB is considered good by today's standards.
If you ever upgrade beyond this in the future, then you will be looking at a new CPU, motherboard, and DDR4 memory (assuming DDR5 is not out by that time), and so on. DDR4 will not fit in LGA 1155 motherboard.
I am pretty certain that, once you have the motherboard, the GTX 1050 GPU would be the weak link. The first upgrade I would make, once the GPU prices come down to normal, is for a GTX 1060 (6GB).
A free CPU is definitely a good start! Are you certain it's in good working condition?