the in-game tutorials suck. they are misleading, and even the good ones you can't see again in the menus later on. i think
chuggaaconroy's video (https://www.youtube.com/watch?v=b8P7KhFSA2w) is probably a decent place to get situated. enel's videos are also outstanding for mechanics but he does have some party member spoilers in them, and most are focused on postgame anyways.
after a bit of frustration, when it first clicked on my first playthrough i was like "omg i have to tell everyone this game is awesome the battle system is genius"
they're not that bad, definitely not as bad as, say, getting spoiled on the seventh party member in xc1, but the xenoblade community has been very vigilant about avoiding spoilers so i'd like to keep that tradition up here :)
the enel video i would recommend to a newcomer is https://www.youtube.com/watch?v=GEksqxaML58. i like it a lot better than the chugga video personally actually as far as explaining combat goes.
and i just rewatched both of these videos since it had been a hot minute. the only thing i would add is that you must view your blade's affinity chart in order to unlock nodes on the chart. if you see the notification that you completed the requirements, but don't go back and view the affinity chart, that node will remain locked and no progress will be made on any nodes following it.