But I founded Charisma important... so 5 for it.
Charisma is useless. Yes, you get +2 Speech and +2 Barter for each point of Charisma and Speech is a useful skill. But if you want a high Speech skill it is better to simply put more points into Intelligence.
Let's say we have two characters. Bob has 5 INT and 5 CHA and Joe has 9 INT and 1 CHA. And they both have 5 Luck and make Speech a Tag skill. Bob then starts with 30 Speech and Joe starts with only 22 Speech. But Bob only gets 15 skill points at each level and Joe gets 19. If they put all their skill points into Speech then at level 2 Bob will have 45 Speech and Joe will have 41 Speech. At level 3 both will have 60 Speech. And at level 4 Bob will have 75 Speech while Joe will already have 79. At level 5 Bob has 90 Speech and Joe has 98. And then at level 6 both have 100 Speech, but Bob only has 5 skill points left over while Joe has 17 skill points left over. From here on both will have the same Speech skill, but Joe will be the stronger character because he has plenty of skill points that he can put into all sorts of skills.
So as I've said, Charisma is useless.
Onlike TES, in Fallout 3 we don't get higher stats by training them, it's when we go a level that we can get them higher.
What he's trying to say is that you don't level up from increasing skills, you increase skills from leveling up. You get experience for completing quests, killing enemies, hacking, lockpicking, succeeding in Speech challenges, and maybe some other minor stuff. Whenever you get enough XP you level up and then you get a number of skill points that you use to improve your skills. Your SPECIAL stats mostly don't change, though you can increase them with the bobbleheads I mentioned before as well as with some perks. Perks are special abilities that you get to choose each time you level up, though you can also get certain perks through quests.