Wiktionary
fend for oneself
vb. To take care of oneself without help.
Usage examples of "fend for oneself".
Anything must be preferable to being turned loose to fend for oneself in the barren waste to the north, where no plants grew and there was a constant risk from icefaws and snowbelongs, which colonized the bodies of their prey to nourish their brood-mass.
For a youngling, alone, the Gate's too pricey a place to fend for oneself, so I took to the roads.