Climb a rock, make sure it can’t climb too, then shoot it with tranqs. I managed to knock it out with 3 trans arrows. Mejoberries are better than the other berries. Takes awhile to tame.
Hope this helped. :)
For a low lvl player a lvl 1-45 is good enough to get you going but when you get the kibble a lvl 116-120/150 should be your main goal. High damage means more metal per hit & weight is your 2nd most useful stat to carry more. P.s taming a lvl 145 ankly now ;)
They are very slow and can't turn around very easily. So come up behind one and shoot it with tranq arrows. You should be able to knock it out before it turns around and attacks you. But don't get too close!! Watch out for other Ankylosaurus too. They are travel in herds