It really varies and comes down to preference. I think the body armor and weapon are the two most important pieces of equipment for melee. Leg armor is not very important, and head armor is only going to see any real difference when you start getting up to the 45+ armor levels. I'd suggest going for a "mail" armor type of build as a new player (so "light medium" or "higher tier light armor"). I'd buy body armor in the low 3,000 gold cost, up to low 5,000 gold cost as a new player. For your weapon, I would most likely use whatever you think is good, and not worry about the price.
I personally bought equipment and used it on my first gen as soon as I could. That being said though, it's good to have a buffer of 5,000 gold or so in case you get hit with an unlucky streak of upkeep.
Upkeep is roughly a 4% chance of happening on every piece of equipment for every "XP/Gold tick" you get on the minute marks. If you get hit with upkeep, it will be 7% of the total cost of the item. This is of course, out of "infinity" so it's possible to get hit with upkeep 10 times in a row on the same piece of equipment (though unlikely).
As an early level player, I'd mainly focus on leveling up and getting better gear (rather than how well you're playing). Focus on trying to help/assist other teammates, rather than trying to be a hero yourself.
san. posted a nice chart for calculating athletics and how weight affects you:
Also, I'd highly suggest playing while in a teamspeak for a faction. They likely can answer questions for you, and possibly allow you in their faction to test out using different armor and weapons they have in their armory.