Head to herbivore island off the south east shore. Try to bring a pulmenoscorpius or beelzebufo for topor attacks. Knocking it out wont be too hard on those mounts but if you don’t have one hop on the cliff above everything and fire away a bow crossbow compound bow or gun. Berries aren’t too hard to find just remember to keep narcotics on you just in case. In the time it takes to tame it you could start making a second base on herbivore island because it has metal infused rocks.
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