There are a few trial there for you to hike at Bako National Park.
Check out this website for more of the details of the trail:
http://www.sarawakforestry.com/htm/snp-np-bako.html
We went for the TELOK PAKU trail. It was amazing! I was amazed by all the nature there while hiking on this trail.
However if you would like to closely look at the rocks as shown bellow, you would have to take a boat ride there again to have a closely look at it. You are not able to look at the rock like this from the beach.
How to get there?
There are two stages: (1) first by car, then (2) by boat.
(1) make a ride to Bako Market, the Jetty to Bako National Park is nearby there
* it takes about 45 minutes (or 1 hour) to reach Bako Market if you are departing from Kuching city centre
(2) buy a boat ticket (RM15 for Malaysian and RM20 for foreigner) at the Jetty. The boat will send you to Bako National Park
* it takes about 10 minutes from the Jetty to Bako Notional Park by boat
MAP - Direction from Hilton (Kuching city centre) to Bako Jetty
https://goo.gl/maps/5CtFS