Have you searched oon the forum. It is what it is made for… 
You can get measurement for a particular sensor or monthly archives etc.
If you are new don’t try to use the parquet…
Are you used to open csv with Excel or OpenOffice?
Only P0, P1 and P2 are relevant
P0 = PM1
P1 = PM10
P2 = PM2.5
Search on the ftp pages by sensor name: SDS011, BME280 etc.
For batch download and analyse you would need someone who can code in python or in .R. It is quite complicated to explain here if you have no experience…
Hints: csvgrep, regex etc.
And this but you have to adapt for the new URL: