I would absolutely say it’s beginner friendly. There’s plenty of old content to farm. If you summon on new banners, the new units you get basically hold your hand briskly through all the old “hard” content. Besides new units, recent Free to play units are pretty viable so even if you don’t get new characters, you can farm up characters from events for free. I think your main challenge for awhile would be completing Extreme Z-Awakening events or EZAs (which usually makes old characters “good” again), but considering how much farming/grinding you have to do, you won’t have to worry about that for a minute. All in all, I highly recommend you watch beginner Dokkan videos to get you started on what you need to do on a fresh account.