Would you mind writing some examples in Polish? Pretty please?
Lol… okay…
“Szanowny Pan” (m), “Szanowna Pani” (f) (usually “Sz. P.”) - “Honourable Sir/Mister” or “Honourable Mistress/Madam” (“honourable” is an adjective of “mister” and attaches strictly to it, instead of the person’s name which follows)
“Wielce Szanowny Pan” (usually “W. Sz. P.”) - “Greatly Honourable Sir/Mister”
It’s not actually the same as “honourable” in English styles. It’s somewhere between “respectable” and “honourable”, I guess.
Then you have:
“Wielmożny Pan” (usually “W. P.” or even just “WP”) - while it translates as “Magnipotent Lord” in the most exact rendition (it’s an archaic phrase and it was an exaggeration already when only nobles used it, but it actually survived through commie times

), it will be used even by a father writing to an underaged son.

It’s simply the default envelope address.
Some really misguided people will upgrade it to “Jaśnie Wielmożny Pan”, which was only used with regard to very powerful nobles back in the time, like holders of great benefices. By extension it was given to lesser nobles as a matter of a polite exaggeration. It literally translates as “Serenely Magnipotent Lord”, which is enough to confuse anyone relying on the English translation.
Names of offices only go with the lower style - the “Szanowny Pan”, say, “Szanowny Pan Prezydent” or “Szanowny Pan Minister” or “Szanowny Pan Dyrektor” - in such cases, there’s no abbreviating to “Sz. P.”, as a rule. Business stuff comes to “Szanowny Pan”, as well, or even just “Pan…” or simply the name and surname (which is impolite). The higher style, “Wielmożny Pan”, is generally only used in private correspondence and only on the envelope, not in any other place.
Please note that “Pan” without any adjectives is naturally understood the same as “Mister” in English, so it’s not “Lord”.

Similarly, when we call people “Pan” + first name, it’s done pretty much the same way as the British “Sir” + first name, except it’s a little informal and it’s given to anyone you’d call “Mister”. If you aren’t using the person’s other title, surname or first name, “proszę pana” is the default direct address. Grammatically, it’s actually a verb with an object, but it means pretty much the same as the English “sir” when used to address people with respect (“proszę pani” to a woman). As a rule, “proszę pana” is more formal than “panie Surname” (“panie” is the Vocative of “pan”), which is more formal than “Panie First Name”. “Panie Other Title” is generally the most formal and the most respectful. These days, professionals say “Panie First Name” when they don’t want to go by names alone. “Panie Surname” is nearly never done. “Panie Title” is only used when the title is somewhat prestigious (director, manager, academic degree, military rank above private, names of some professions or functions) or when you don’t know anything but the person’s function - say, “Mister Driver, could you please…”
I know you’re totally confused now.
