Very straightforward; so you want to take the HUT coins you earn from the Tutorial (any way really) Head over to the Auction House and hit 'Y'.
Here, you can filter what you want to buy. Player Items are generally the most expensive, so if you're just looking for a cheap item, filter it at the top to either Jerseys or Logos under team information - and then change it to Bronze as well. You can even go further by making a maximum Buy Now to like 150 or 200.
Either way just buy a Bronze item or anything that fits your budget.