FFXIV running slow

[MiniTofu]

New doesn't mean it will run games well. The spec you have is a budget build. Really cheap spec low end.
If you paid $1000 for it. It's a ripoff. OEM (Original Equipment Manufacture), premade computer by company and sell it at least 1.5-2x than the price you can build one yourself.

AMD A4-5000 APU with Radeo HD Graphics 1.5 GHz processor is really low.

I have few computers here which is almost 4 years old and it can run most games really well 60fps+ ($1000-$1500 back in the days) build by yourself. What I am saying, (new and old computer is irrelevant if it can run games or not. It's all depends on the hardwares)

There isn't much you can do about it. You're experiencing high input lag and stuttering while your CPU is struggling to keep framerate and inputs.