For this one you need to buy up every single aircraft, every single special weapon for every aircraft, and every single upgrade part BOTH in campaign and multiplayer.
Notably, this includes the X-02S Strike Wyvern secret aircraft which only becomes available to buy after you clear the campaign for the first time. The plane costs 2 million points.
All in all, this will set you back more than 30 million points.
Clearing the campaign for the first time grants you one-time bonuses for mission completion, so make sure you get those.
When the bonuses run out, Mission 11 is a good way to farm points in single player, but, provided you are not half-bad, multiplayer is the fastest way to rack up points (you can average around 100k per one 5-minute game). I recommend investing in a plane with either QAAMs, SASMs, or, if you are confident of your skills with it, the PLSL. If you use missiles prioritize missile homing and missile speed upgrade parts.