Your team is pretty good right now but seems to me you don't have depth. You'll need a good bench to pass forza juventus and others. Your questrion was about finances though. First thing I'd do is to correct ticket prices. You got 116 000 last home game and that's too low especially if you're about to invest in 20-30k player. At the moment you're losing 10-20k weekly, right? Since I wouldn't sell your good players maybe it's not a bad idea to invest in a trainee. That million you have can be enough for 1 player and running costs but eventually you'll need to either sell one of your good players or trainees which you don't have. Selling good players to stay alive in the game is a bad choice.
If you plan on buying a player I'd suggest you sell your 31 year old playmaker for about a million. Then buy PG and SG with 20k salary. Younger guys up to 25 so they can contribute in future seasons.
PS you still need a good SF...