Here is a video showing one way to cross the Tuito River in Yelapa, Mexico, to get to the beach.
The other way, not shown, is on the path towards town. The steps on the hillside connect the beach to the path to town, just follow the signs. Sometimes when the river drains into the ocean, the torrent is too strong at the beach for some injured, obese or elderly people to cross, so wading the river at some spot is the only option unless you hire a panga boat.
There are accommodations on the beach, but they cost more and as budget travelers we opted for a place to stay a bit upriver in the jungle. (Keep in mind, nothing is really ‘cheap’ in Yelapa, compared to other parts of Mexico, except maybe meals at places in the jungle.)