Weight distribution: red(more) to blue (less)

Object Mode → Select body then bone → Ctrl+P → Automatic Weights
Select bone → Alt+P → Disconnect Bone (can remain parent) / Clear Parent
Need poles for leg and hip joint, and leg and foot joint. Remember to uncheck deform.
leg needs Under Pose Mode, add Inverse Kinematics → Target and Pole Target are Amature, Bone 1 is foot pole and Bone 2 leg pole. Pole Angle needs adjustment if any distortion, chain length = 2.
foot needs add Copy Rotation, Invert Y and Z, uncheck Inherit Rotation. Target: Armature, and Bone footpole, Target and Owner are Local Space.

Tab: switch mode between Object and Edit
Alt+Z: X-ray mode
G: Grap (Move), can expand a point in or out.
R: Rotate
S: Scale
A: Select All
Shift+A: Add object
Shift+D: Duplicate object
Shift+C: Reset Cursor
Ctrl+A: Apply
Shift+Right Click: relocate cursor
X,Y,Z: Can lock to specific axis
Numberpad 3:X,1:Y,7:Z align to axis
Shift+A → Amature: add bone
E: Extrude (bone)
O+?: Cancel ?
Ctrl+Tab: Next next mode
Edit → Preferences → Add-ons ⋺ Search: enable add-ons
Select Amature Layer → Ctrl+P → With Automatic Weights: Assign automatic weight
Under Object Mode → Select Skin layers you need and Armature → Under Pose Mode → Shift Select that one specific bone → Ctrl+P → Bone: Option2 Assign Bone if automatic weight does not work
Ctrl+P → Keep offset: pairing and connecting but keep distance.
Ctrl+A → Rotations → Shift+D → S → X → -1: Copy the object and reflect along X?
Shift D → G+X → Remain Select → Right click → Mirror → Along X-axis: duplicate and mirror along X

Edit → Preferences → Search rigify
Object Mode → Shift+A → Armature → Basic Human (Meta Rig)
Make sure scale and apply scale Ctrl+A
After arranging all the bones to their responsive locations, go to armature metarig sidetab at right → Rigify Buttons → Generate Rig
Then apply automatic weighting.