Hi Lkkoh,
As far as a recommended Minix box, the U-9H is the latest and most capable.
As far as "free" streaming content in the US, that requires choices and first, beside some form of hi-speed internet, do you have cable TV, or ?
To use sports apps from the app store with "free" content, e.g. NBC Sports app, Fox Sports Go app, or ESPN app, once you download one of these apps you will need to sign up/log in the first time you start up. As part of the process, you will be asked what cable or satellite provider you have. Once you enter that and the other requested info, you are logged in and can see what free content is available. This however depends upon what channels you have access to through your cable or satellite provider. For instance, if your service does not include NBC Sports network, you will not be able to watch much of the content. Same with ESPN. Check them out on-line to get all the facts. They also offer additional paid content.
For "free" movies and shows you will have to download the apps and sign up for Crackle, Tubi, Vudu, PlutoTV, which offer free content, but with commercials and generally not recent releases. There are others.
Your only other options are to sign up for paid providers such as Fubo (sports) or Netflix (movies), etc.
Research online is your friend. Good luck.