Get a bow and three sets of arrows. Wait until your first siege and then by the time you're done you'll be level 8ish. Try to steal weapons off the ground too. What ever you pickup you can sell for some cash to buy better armor. I usually eye the "Glaives" or other exotic two handed weapons. Most swords will only fetch around 500 for each one. Be sure to order all archers to follow you so they make a nice line. From there just pick off everyone on the walls. It's boring I know but it's better than getting no xp and dieing in the moshpit in 5 seconds. I tend to make my Father figure an archer ,leader character. I play by a lot of odd rules. If he dies (arrow to the head) I'll load up a new character as his son (reroll).
As for renown, once I have enough money to become a merc, I will get a lance and a very fast horse. You can fight in the one on one tournaments and one hit everyone. Be careful though because if your lance breaks you should have a backup twohander. The goal is to kill him on the first pass, if you can't do that every time then unhorse him then lance him. You'll get 20 renown for each tournament plus what ever you bet. It's 11K if you bet 500 and win, 7K for each one you win after that plus the renown. Since they have multiple tourni's you can fight in the same one about 6-8 times (depends on how long they want to feast). All you have to watch is that it's day time and for when the message flashes across the screen that they are going to continue to feast. Make sure you are dedicating your success each time to a lady.