Youre off to a good start. Looks like a decent bike.
Dont be tempted to rotate the bars to bring the levers back up - as it is in the picture is perfect, forces your elbows up, gives you greater control and endurance.
Pedals are very personal affair. The trend in recent years has been away from clipless off road. However, I still use them off road, unless Im teaching and spending a lot of time on my feet demonstrating stuff and talking bollards. I think in general, and not just MTBs, people move to clipless before their fundamental riding and control skills are sufficiently advanced, and they're the ones who have the clipless 'moments' - skilled riders simply don't have them, even when new to spuds. Therefore, if you're not already comfy with spuds then stick to flats for a bit.
Enjoy!