Hi hi welcome! Although I'm essentially a fossil now compared to most, I am not the most knowledgeable but I can share about how I am still around here lol.
LDS has essentially shared all the basic tips. But firstly you have to know that it's a long game, it takes time to develop players, it takes time to make money, it takes time to build a stadium, and most of all it takes time and some luck to win.
Developing local talents is probably the 'cheapest' way to up your merch sales through homegrown & locals, since everything else takes money. But seeing that you have a 480k profit which is really good, what you need is to think about how to invest them.
If you feel you might get a high draft pick and are ready to take on a new trainee, you may invest up to 6pts/wk to go all in getting a HOF/ATG rookie to develop. I am not the best trainer but LDS and others are here to help guide, and I have developed a number of U21s over the years who helped me stay competitive or at least in the league all these time. From there you can slowly build up your money and squad.
15k/5k/500/50 is a good goal to hit. You just need to figure the right ticket prices to maximise gate receipts and you can consider investing in a arena design or merch store to up the weekly merch sales. Arena sponsorships are based on arena design and merch store also gives a fixed income based on the level of merch store. They however take time to breakeven on the construction costs before you really start to profit so you might have to do a bit of math to see if it's worth it and to manage the cash flow over e.g. buying a star player, investing in scouting, arena expansion and other upgrades etc.
It took me a long time to amass the money to max out my stadium and all infrastructure, after that as long as you can balance the players' salary and other outputs, you can easily maintain the profits and a healthy balance to bring in good players, continue developing local talents, and eventually build a winning team.
The game has changed a lot since I started and there are much more things to look at now. I took more than 20 seasons to consistently stay in SBBL and 40 seasons to finally win my first SBBL title. So the best advice I can give is probably really be patient, play the long game, and keep going!
Hope these helps in some ways. The rest pls feel free to chip in or add on!