If you want to manage at international level straight away, simply do the following. When you get to select a team select for example, England, type your name in as "Glenn Hoddle" and you should now be managing England, and the same for the following international teams.
Free Players
When buying a player enter a bid that will be accepted and go to comfirm. Then go to adjust bid and put the bid to free then click on cancel. Now, if the player accepts to your contract terms you will get him for nothing at all.