Hi. Welcome to the REAL fun with photography.
IMO, step one is to get a good hand held light meter. After a light-tight box with film (or WHATEVER media that respond to light) in it, it is the most important piece of photographic equipment you can have. Unfortunately, it seems that very few people actually purchase them early on and learn them well, favoring lenses and accessories, and a million cameras. It makes no sense, if you are actually after ideal results! A good light meter will last you your whole life (if you take care of it), and will do more than any other piece of equipment to allow you to idealize, perfect, and predict your results.
I am partial to the Sekonic incident light meter models, the Sekonic L-398A Studio Deluxe III, and the Sekonic L-208 Twinmaster.
The former is a light meter that is time proven, the first ones having been introduced over half a century ago, with
very few (i.e. no, in all practicality) changes having been made since. The one I use was made in the mid '50s, and is at most only 1/6 stop off from a brand new one, and the light meter guy in Hollywood sez this is only because the dome has yellowed a bit (an easy and cheap fix, but why bother if results are good, he sez). I got three of the meters for about $20 off of E-Bay. One to use, two with very darkly yellowed domes to use for parts (cases, high slides, etc.).
The L-208 is a lower-end model, but works great. It doesn't have all the nifty accessories like high slides, lumidisks, etc., but if all you ever want to do is to take a simple ambient incident light reading, it is a great meter. Simple, cheap, small, well built. It also allows reflected readings, if you should want such a thing.
There are also plenty of other great old, classic, time-tested meters. Gossen Luna Pros, for example. I am most familiar with Sekonics, however, so someone else can give you all the grisly details about these.
There are also new electronic multi-fuction ones. These are good if you use flash and ambient light. They are a bit more bulky, however (and IMO poorly made and overly complicated to use). They are also a bit pricier, in general, being multi-functional meters.
Then, you get into actually testing the film to find out how to expose it and develop it to get what you want in your prints.
There are two points to think about initially, before doing anything: One is that Pan F is a contrasty film, and therefore it does not hold shadow detail well in anything but a relatively low-contrast composition. The other is that Perceptol will only exacerbate this by lowering density across the board, compared to a more "standard" developer like ID-11 or Ilfotec HC.
So, in practice, Pan F with any developer, but especially with Perceptol, is going to need to be given additional exposure to give you a "normal" amount of exposure in the dark areas, if exposed in a "normal-contrast composition." I am not saying that the film is not ISO 50, because it is. (ISO is ISO is ISO.) I am just saying that it is a contrasty emulsion, so if you expect it to behave like the 100 and 400 films to which you are probably used, it will need some tweaking.
Next, I would go ahead and make the investment in a photographic test target. It is hard to understand why you would spend so much on a stupid flat object with some colored squares on it, but it should last forever, and it is a tiny investment in the grand scheme of things. It is another one of the most helpful devices out there, and another one that hardly anybody uses, especially when first learning. This doodad combined with a good light meter will tell you so much about any film and developer combination, and will do it quickly and easily. Look for MacBeth Color Checker charts or other similar charts at photo stores. They give you a quick look at exposure, contrast, spectral sensitivity, and development. With color film, they tell you even more.
I prefer a single exposure of a test chart to all other methods, as it shows you in one simple shot how your film naturally behaves when exposed and developed a certain way. Bracket exposure and development pix of the chart, choose the one that you like best, and you have your exposure compensation (which can be applied via EI changes if you choose) and development just like that. However, without the chart, you can just use your camera controls to expose a neutrally-hued piece of card or paper to different tones of grey, and then print them at a "normal" time to see how they are rendered in prints. It's more complicated and labor intensive to figure everything out, and you don't get to see everything all at once, but it works. (It is how Zone System tests are done, in fact.) This method is quickly and easily explained in Ansel Adams' book, "The Negative", in the Zone System chapter and the technical appendices.
I personally prefer to always rate a film at box speed, learn how it behaves with different exposure and development (i.e. what kid of contrast it has when treated a certain way), meter for a midtone (incident metering), and manually apply exposure and development alteration in each scenario based on what I want, the lighting and composition, and on my testing of how the film behaves. Others prefer to use a "permanent", across-the-board EI tweak as a way to fit any film into a certain mold based on what they have decided that they generally want shadows and highlights to look like on a print. Either method works fine. You just need to find what works for you, and then be consistent in using this method.
So, in short, IMHO, get a good light meter, get a good test chart, bracket exposure and development of the pix you shoot of the test chart, print the pix of the test charts, pick the test chart print that you like best, and use the parameters (exposure compensation and development time) you used for that shot in the future. (Take good notes throughout, otherwise you don't know what the heck is what.)
