Hey gorski,
Welcome to the game, and congrats on a great start to the season!
The first thing I'd do is to check if there is any "dead weight" on your team -- players you think will never see the court, and will only eat up a chunk of your salary budget. I'd try to sell these guys on the transfer list ASAP, and fire them if you can't sell them (I see you have two players for sale already). You can probably cut down to 13-14 players or so with no problems.
Next, I'd look to see if there are any holes in your lineup where your team could be stronger. If you see any big ones, I might consider investing in a player for that position. Either get a veteran (25 or older) if you're not planning on training him, or a young player (18, maybe 19) if you want to train him. In order to choose which one you want, you'll need to figure out which area you want to train (do you have any young players with high potential? they're probably your best bet).
Hope this helps you get started!