Guys, guys, you're looking at this from the wrong angle. The dude's not a Bard or a Fighter, the dude's a thief: he's a Rogue. He flat out said he stole the equipment.
Personally, I'd start with Rogue at level 1, then go Fighter from then on. In D&D you can mix different classes together to gain benefits from both. It's called Multiclassing. A Rogue+Fighter is a good combination.
Rogues can't wear the knight's chainmail armor correctly at level 1 (Rule of Cool: ask your DM if you can just "remove the DEX mod bonus to AC until you're proficient in it", he'll know what that means so ask him to explain it to you), but that's to be expected. After getting some experience using the armor (and leveling up), then you become proficient in it (by multiclassing into Fighter) and get the DEX mod back. It's breaking the rules to support your character's cool backstory, but if you're gonna learn anything about D&D, it's that the rules don't matter much when it comes to roleplaying games. You're here to have fun and go on adventures with your friends. The written rules are great suggestions for balance, but the DM is "god" and can break them as he sees fit. Read the preface Mike Mearls wrote in the Player's Handbook about this.
A Fighter X/Rogue 1 is a nice combo for a new player. You don't have to worry about spells, so it's still relatively easy to learn, and you get 2 fantastic features to add to your Fighter's normal skills: Expertise and Sneak Attack. You shouldn't limit your options to something simple, because 1) that's boring, and 2) the best way to learn the rules is to play. It's all simple once you become familiar with it. We didn't start out knowing how to play Rogues and Bards and Sorcerers; we made cool characters and learned their strengths and weaknesses by playing them. If you have trouble and want suggestions, then ask the experienced folks around the table. They'd love to answer your questions and get you excited about your character. Take risks, get creative, piss off your DM, and have fun. That's what D&D is all about.
Personally, I'd start with Rogue at level 1, then go Fighter from then on. In D&D you can mix different classes together to gain benefits from both. It's called Multiclassing. A Rogue+Fighter is a good combination.
Rogues can't wear the knight's chainmail armor correctly at level 1 (Rule of Cool: ask your DM if you can just "remove the DEX mod bonus to AC until you're proficient in it", he'll know what that means so ask him to explain it to you), but that's to be expected. After getting some experience using the armor (and leveling up), then you become proficient in it (by multiclassing into Fighter) and get the DEX mod back. It's breaking the rules to support your character's cool backstory, but if you're gonna learn anything about D&D, it's that the rules don't matter much when it comes to roleplaying games. You're here to have fun and go on adventures with your friends. The written rules are great suggestions for balance, but the DM is "god" and can break them as he sees fit. Read the preface Mike Mearls wrote in the Player's Handbook about this.
A Fighter X/Rogue 1 is a nice combo for a new player. You don't have to worry about spells, so it's still relatively easy to learn, and you get 2 fantastic features to add to your Fighter's normal skills: Expertise and Sneak Attack. You shouldn't limit your options to something simple, because 1) that's boring, and 2) the best way to learn the rules is to play. It's all simple once you become familiar with it. We didn't start out knowing how to play Rogues and Bards and Sorcerers; we made cool characters and learned their strengths and weaknesses by playing them. If you have trouble and want suggestions, then ask the experienced folks around the table. They'd love to answer your questions and get you excited about your character. Take risks, get creative, piss off your DM, and have fun. That's what D&D is all about.