I would buy the MLS, and change a bunch of its rules. For one, I would get rid of the rule that each team could only have 3 non-Americans or something like that. I would make it 6 or 7. Secondly, I would give all teams control of their players, not the MLS, so if a team wanted to sell a player, they could without the MLS' approval. I would then buy a team, the MetroStars, and build a new 60,000 seat stadium in Harrison, NJ (they want to build a 30,000 seater, but I'll get to why this will make sense). After that, I will buy David Beckham, yes, David Beckham. Beckham has previously stated he would like to be famous here and there are a lot of Manchester United and Beckham fans here in the New York area. With Beckham, we will sell out every game. With the increased revenues in MLS, other teams will gain popularity, and the sport will gain popularity as well. This affect would create more good players in the USA, and help our national team. Also, more players would want to come to America.
I also forgot to say that I would change the format of the MLS season. The season would start in August and end in June, and would include a 2 month break from the middle of December through the middle of Feburary since that is the coldest time of the year, and for some MLS teams (Revs, Metros, Crew, DC United, Chicago, Kansas City) the weather would be too cold to play soccer.
After that, I would buy the Blackburn Rovers. I would continue to develop their youth academy. They need a striker, so I would get Fernando Morientes from Real Madrid for 12 million pounds. He would at least play there, and I would also buy John O'Brien where he could play in the central midfield, something he can't do at Ajax. I would also solidify my defense by signing Carlos Puyol from Barca, as my big signing. I would cap all of this off by bringing Damien Duff back to Blackburn, although I am not sure if that evil man Abromovich would sell him back.