Fighter/Mage Fluff Help

Hey friends, new to the game (completely blind) and wanted to make an Elf Fighter/Mage since I just really like martial classes with a bit of magic and games and I find Elves neat. The reason I'm here is because some friends of mine and some things I've seen online have VERY adamantly said that you should pretty much exclusively use 2 weapon fighting. I'm not much of a fan of 2 weapons so I was wondering what you guys thought would be more fun or flavorful for an Elf Fighter/Mage between a 2 handed weapon, single weapon or sword + shield (THAC0 bonus for Longsword sounds useful but I don't fully get just how good THAC0 +1 really is). A discussion about either usefulness and/or flavor is also welcome! Thanks!