It looks as if the reel may never have been reground, so you should be able to get a very long life from it before you need a new one (which is expensive). It also has a Briggs and Stratton engine, which is likely to be the original one, increasing the likelihood that your mower has not been used commercially. This again is good news. After you do the basic maintenance, make sure that the reel is not physically touching the bedknife as it rotates. (Don't try to adjust it until you've done some research on the process, though.) If there is no reel-to-bedknife contact, once you've done the basic maintenance you could try using it and getting the hang of it. Once you are through that stage you get to the advanced course: blade adjustment. There is plenty of information on that in past threads here.
