Time for an oil change

So im about to change my oil(firsttime) and im wondering whats the best kind(brand/type) of oil for a 4th gen lude like mine?? suggestions?? and what kind do u guys use? and do u guys recommend that sealant stuff that help prevents engine leaks and whatnot.

whatever 10w-30. check what thickness you need to get depending on your climate. if it's not leaking, then no need to put sealant.

thickness??? and ive heard that "all synthetic" oil or some shit is best.