In a word, no. There are examples of complaints against individual police departments investigated by the USDOJ that lead to an MOA, Memorandum Of Agreement. One example I can cite is from the Prince George's County Police Department in Prince George's County, Maryland. In the MOA, they agreed to use dashboard cameras, and body camera technology wasn't as evolved in 2004 as it is today. The DOJ might well insist upon wearable cameras today for such complaints.
No, local police are under state/local control and the president runs the federal executive branch. The president isn't even really a policy maker- that role falls to Congress. But even congress can't dictate a camera program because their control doesn't extend to local police. This exact issue was litigated in the early 90s in Printz v U.S. (1997) when congress passed a law commanding local police to carry out a federal policy relating to gun control.
- the president could petition congress to fund a camera program, but only make those funds available to states that have a camera policy governing police in their jurisdiction. Funding with conditions is a valid exercise of Congress's spending powers. This hinges on whether the states take the bait or not. They could forgo the funds and not create a camera policy (which they might do if the funds provided were not actually sufficient to fund the mandate).
- the president could have the DOJ civil rights division initiate litigation against police agencies that it feels have violated federal civil rights law and then offer to dismiss the suits if the agencies enter into consent agreements that include a camera policy. This depends on the sued entity choosing to settle rather than litigate. If they litigate and win, you get nothing. If they litigate and lose, the judge might still not give you a camera program.