I'm... not sure what you mean by the second statement.
By the first, assuming they meet all prerequisites (which means we're looking at 2e here, no Kerisgame hacks):
Let's not take White Veil Style for our example, since it doesn't exist. According to Scroll of the Monk, it does not consist of 8 Charms in total. Scroll of Heroes (why are you making me look at these books) tells us that a Martial Arts Charm requires (Minimum Ability) weeks for a mortal who favours Martial Arts to learn it.
I will assume your hypothetical mortal has Martial Arts favoured.
So! If White Veil Style existed, it would have Birdsong Over Blades (Martial Arts 3), Alehouse Memory Stance (3), Owl Clutches At The Night (4), White Veil Form (4), Blinded By Laughter (5), The Dragon Dies In Bed (5), The Dragon Dies Screaming (5), and The Dragon Succumbs (5).
3+3+4+4+5+5+5+5 weeks, making 34 weeks in total- keeping in mind that years in Creation are 60 weeks, that's a little over half a Creation Year.
This is, of course, assuming that you are already at Martial Arts 5 and Essence 3 and have all the required experience already. If not, it will take
years to accumulate the required skill, enlighten your Essence to the needed levels, and learn the Charms.
And, of course, it would require White Veil Style to exist.
Which it does not, obviously.