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They are two main approachs for humanoid robot walking. Practically it depends on the physical capabilities of your robot and what you want to achieve.
If your robot is able to sustain strong impact and you aim at cyclic walking on uneven terrain I would recommend to try the Hybrid Zero Dynamics approach. The current best example is the Cassie or the Digit ...
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Your LIDAR will need some active stabilization. Under gravity alone it will sway like a pendulum.
You could start with a web search for "servo gimbal". Resulting hits show complete devices, arduino projects, tuning strategies, hobbyist guides, etc., for drones, copters, UAVs, etc. Your LIDAR mount might benefit from work done for mounting cameras. ...
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