Pay attention to "Line Management" and "Line Equalizing"! Isn't any fun to get on the field, only to find lines are a mess! The method John uses is almost foolproof, learn and use it - EVERY TIME! Learn to make the method a habit!!
Equalizing is very important - even on new lines!!! Take them out, stake one end to a single fixed object, put your handles on, then compare how the 2 handles line up! Should be EXACTLY the same, if not, adjust as needed! You don't need an off line causing the kite to steer itself and fight you!
I see you're getting an SLE, it doesn't come with the longer leaders of a "B", so I would encourage you to make some yourself! Just be sure both leaders are the same - ie, knots the same distance from handle on both, etc! You only need to make new top leaders, the bottoms are OK just the way they are now!! John also has a tutorial on why the leader idea works!!
Have fun, BREATHE, and if the kite is gonna crash no matter what - GIVE TO THE KITE!! Step forward, throw your hands forward, take all the power out, and let it crash - gently!! Easy enough to go set up again, no fun putting up a broken kite!!! You panic and pull - just drives the kite harder into the ground!!