Hi, im a New One...

Can i post Single runs ( MEC ) or i need a full NG+ or so on? Im new in running and learning...

Well, check out the Mirror's Edge Catalyst leaderboard: https://www.speedrun.com/mec There are several leaderboards for full game categories, and there are also leaderboards for each individual level (You can switch between full-game leaderboard and level leaderboard on the left menu).

You can run whatever you like.