Well, if you are looking easy archetypes (you seem to think Paladin's all have a single personality), then if you want to play a LG Wizard I suggest you channel the 'Gandalf' personality. Gandalf is LG, but he tends to be a bit quick tempered and a bit caustic at first. He loves to joke and to laugh, often at other peoples expense. He very much is a believer in 'tough love'. But at the same time, he melts easy, forgives easily, and becomes kind whenever he is dealing with someone who is acting without guile or malice. He's cocky and a bit arrogant, but at the same time he's devoted his whole life to humbling himself. He never shows off. There isn't a shred of pretense or affectation in his whole body. If he's comes off as a bit arrogant, it's because he's utterly lacking in false modesty. Yet, perhaps oddly, this lover of truth has become a master or illusions, of shadow magic, concealing smokes, and stealth... which he uses exclusively to uncover the truth when people try to conceal it.
In general, when making any character, it's good to ask questions like the following:
a) What does my character want most from life? This could be almost anything: wealth, fame, to see justice done, to impress a parent, to acquire knowledge, to save his people. As you get more skilled at RP, you start to get the ability to play characters that are complex, like a LG character that is seeking his fortune or a CE character that wants to see justice done.
b) What failings does my character have that puts him in tension with his own goals? It's good to have a foible that isn't particularly disruptive. Again, this can be complex, particularly in characters that don't know themselves well. For example, you might have a CN character who has a streak of honor or compassion that keeps getting in the way of his own beliefs, or at least, what he believes his own beliefs to be. Complex characters often misjudge their own alignment or misunderstand their own motivations. Realistically, any character with less than an 18 WIS will have some fairly obvious failing, and the lower the WIS the more obvious it will be.
c) Who does my character care about? This can either be a specific person (a parent, a younger sister, the king) or a class of people (members of his own nationality/ethnic group, the poor, the oppressed, the powerful).
d) If they really care about that person, why are they adventuring? Of course, the answer could be, because they are in party, which makes for an interesting dynamic if another player agrees to play your best friend, relative, or romantic interest. Don't push that on anyone that doesn't want that complication though.
e) What trait does my character have that would show up in a first impression? Technically, this isn't necessary and it tends to make characters a bit shallow to have an obvious trope, but RPGs IMO need to create characters that are memorable even after a very terse characterization. You don't have a whole novel to expound on the subtleties of the character. You want everyone at the table to get at least something about the character right away.
f) What can I give the DM to create a hook regarding challenges I'm willing to have thrown in the way of my character? Do I have a foil or nemesis in my backstory? Have I made a big mistake or suffered some injustice in my immediate past? Do you have a secret you need to protect? Obviously, if your DM sucks you'll want to avoid doing this, but if your DM sucks why are you playing? More sophisticated groups will be able to deal with more sophisticated problems without derailing play. Start small.
