Why my new laptop(Acer Nitro 5 AN515-54) is slow?

Go into Settings, then click system, then power and sleep, and on the far right hand of the screen you will see under related settings "Additional power settings". Click that and then it should open up a setting in control panel. On the far left hand you will see create power plan. Click that and then click high performance and name it whatever you want. Click next and set all the options to never. Click create once you are done that. It should automatically equip the power plan once you create it. 
Now press the windows button and R at the same time and it should open up something named run. Beside the word "open" there should be a text box where you can type in. type in the word temp and click ok. it should open up a bunch of files. You can delete all of these files, they are basically deleted files that for some reason are still stored on your laptop. it might say you don't have permission to access this, just ignore it or click ok. Or, it might say something like "Unable to delete this file", just click skip. you can now exit out of your file explorer.
Now you have to press the windows button and R at the same time and type in %temp%. This will open up extra junk files stored on your computer, just delete them all.  it might say you don't have permission to access this, just ignore it or click ok. Or, it might say something like "Unable to delete this file", just click skip. you can now exit out of your file explorer.
My laptop came with over 10,000 of these junk files.
Now the last and most important step is to go into recycle bin and then delete all of the files there. This is the most important step so dont skip it otherwise there will be no point of deleting those files. if you have any other questions you can reply, but I am not much of a tech guy. If this doesn't work i suggest you return the laptop and buy it again so you get a different copy of the laptop, that may help. if that doesnt work then just contact acer. 
Also, it is very strange that your computer is running that slow. This usually happens if you have gotten some sort of malware or virus on your computer, so check your computer thoroughly.
Hope this helped.

Quick question have you recently updated the laptop? and can you go to device manager and see if you`re nvidia card is working fine?