$50 for the lot or just the RO unit?
Bargain if it was the latter.
Still a bargain for just the RO unit.
Dump the water that is already in the container.
I can't quite see it in the picture, but looks like you will need the 1/4inch tube to faucet adaptor.
Best to talk to FSA to determine what faucet adaptor you need.
After getting that adaptor, hook it up and get some RO water from it to determine if you need to change filters by testing the TDS.
The filter might still be ok. I usually change filters when TDS is above 10ppm. Could probably change earlier, but I'm trying to save on filter costs. So I make it run longer by changing only when TDS is above 10.