I think polearms are a versatile group of weapons and a good choice as you get a feel for the game. That build is solid, but I would recommend putting a few points from ironflesh and maybe one from weapon master into shield. Until you really get the hang of manual blocking, playing with no shield will lead to a lot of frustrating deaths. You won't be gimping yourself by putting points into shield, and even if you level it up you don't
have to equip one every round you play.
As far as paying for items goes, look at your character's inventory on the website. See the number 'upkeep (max)'? Try to keep your default gear under 1,500 max upkeep. If your team loses every single round you should still be able to maintain or slowly build gold with that much upkeep. Every time your team wins, your multiplier goes up. At 2x you can "support" 3,000 upkeep, 4,500 at 3x, etc. If you keep your default gear at higher multipliers, you will quickly build a stash of gold.
As you level up and gain more gold, expand your inventory. Have a basic cheap weapon (boar spear or plain old spear), then pick up a few more specialized ones like a pike or, long axe, or swiss halberd. The red tassel and war spears are great direct upgrades of the short/boar/regular spear.
You don't have to do this, but when I start a character from level 1 the first thing I level up is strength/power strike before anything else. Convert skill points to attributes and get your strength up to 15-18 with PS level 5-6 before you level up anything else. You get a big pool of hitpoints from the strength, and will be able to use pretty much any weapon or armor you want very early on.
In battle, don't rush off by yourself. Even if you are skilled and have the best gear in the game, you won't win a fight against 15 people by yourself. Hang back and watch your team's movement. Stay in a group. As a polearm user, you can probably hang behind 1h/shield teamates and land spear thrusts on the enemy they are fighting.
Most of the mechanics are very similar to default M&B, with tweaked numbers. If you keep playing, you'll get a feel for almost everything. The only major difference I can think of is being able to make a shield wall. If you and your teamates hold up your shields near each other, you gain a temporary bonus to your shield skill. As long as you stay together in formation, your shield will be able to absorb a LOT more punishment, and have an increased radius.
Have fun, and good luck. Try out plenty of stuff on your way to level 31, it will take longer than you think!
edit: keep an eye out for polearm weapons that dead people drop. Find a masterwork awlpike or glaive on the ground and you've got a 1,200,000 gold item in your hands (till you die or the map changes)!