But if i am being like a jack of all trades kinda guy wouldnt that make me more versatile also? What if a monster is immune to magic but deadly up close, i will have some archery experience to take him out or something.
There is a lot you have to take into consideration, mainly with health, magic, and stamina. When you level up, you can level these up, but if you go for 1/1/1 than you will be outdone very easily past level 15 when the enemies start getting tough. Dragons in particular are very powerful opponents early off, and by investing in something that will put you at a disadvantage, than you will quickly tire and bore of your first character. It is better to specialize in one type of character like an archer, warriors, or mage.
Archers are perfect for taking units out at range, and arguably the most fun of the types, and also is helpful for assassins as well. They specialize in sneak, archery, light armor, and enchanting for the best results.
Warriors can consist of two variants, either the two handed or one handed. The two handed warrior specializes in two handed, heavy armor, and enchanting to get the most out of his build. The one handed warriors combines good armor with good blocking to be a near unstopable tank that can also deal out good damage. Both classes also specialize in the heavy armor perk tree to have the best heavy armor available.
Mages are perhaps the most versatile of the groups. You can be a warrior mage specializing in destruction magic to overwhelm your opponents, or you can be a conjurer to conjure mystical beings to do the battle for you. Than you can be the master wizard type that specializes in all the magic trees to have the most robust of the builds.
Normally, a robust character might be good early on, but after ten or so levels, you will learn that it was actually a mistake. Also, all enemies are weak to magic, just some more than others.
And do people really start new characters all the way from the dragon attack in helgen? If you already have a character do you get boosts or something?
Yes, people do this all the time, me included, after a while, it isn't all that bad. You do not keep all the boosts and have to regain them all over again.