Welcome! You should start out by reading the Guide To BuzzerBeater + FAQ in the help forum. For now, spend the money you have on your arena. Don't buy new players right away. Keep the players you have right now for a little while, and only buy solid players, with 7k-12k salaries. Use the Transfer Price Estimate to help you decide how much the players you're bidding on are worth.
Good Luck!
Put Name Here