Finally playing Madden FR

Finally going to try a deep dive career with my Miami Dolphins, but I struggle so much playing. I’ve had 3-5 versions of the game but can never enjoy it due to being ass on defense and not fully understanding cap and trades.

How do y’all control defense ? I’m stuck between LB or safety, what’s best ?

Is there a “losers guide to Madden” to watch on YouTube ?