Demo Sample

Well, the reel shows you have learned the basics of how to handle 3D Studio and that's a start. However, as I see it you must learn a lot more about basic animation principles. Your poses look too generic and symmetrical and your timing is too smooth and even.
Animating a character lifting a weight is a common exercise of advanced principles which you'll find in all animation books worth their salt - do compare what Eric Goldberg and Dick Williams write about it with your effort so far, learn to recognise what you failed to do and then add what you missed and enhance what's already there.

My two cents on the weight-lifting scene you animated:

-good idea to have a little lead-up to the main action, like the character waving to an imaginary crowd.
However, your character's body segments seem to rotate mechanically around their joints which kills believability. For example, when the character waves, only his arms move. I'd suggest making the motion stronger - don't let the hand lead the action, the force comes from the shoulder, arm and elbow. Create some overlap in the hand.

-when the character bends down to reach for the weight there's no real anticipation in the broad action. Let his body go up first before going down, delay the arms or a combination of both. Experiment. Delay one arm more than the other, for example, so that one hand reaches the weight first. Mechanical symmetry should be avoided in animation unless you're animating a machine or robot.

- good idea to have the character focus and concentrate by having him remain in his crouched position for a few moments before the actual lifting starts

-to create a better illusion of the weight lifted you can do more than just have the character come up more slowly. What if he strained against the weight without at first being able to lift it from the ground? If it's possible with the rig you're using, try stretching the limbs.

-overall, broader, better defined poses will make the action clearer. The trembling knees are a good idea but barely noticeable. Let the action get broader and funnier. Why have the guy quit after only two attempts? Let him overstrain himself more and more, really fight with the task. Audiences tend to like characters with a strong resolve - especially if the task is hopeless and the attempts become more and more comical.

There's more to be said, I'm sure, and hopefully others will provide more input. You'll only learn if you discover for yourself, though. All I can really suggest is to keep in mind the basic principles of physical animation:

[LIST]
[*]
[LIST=1]
[*] Squash and stretch
[*] Anticipation
[*] Staging
[*] Straight Ahead Action and Pose to Pose
[*] Follow Through and Overlapping Action
[*] Slow In and Slow Out
[*] Arcs
[*] Secondary Action
[*] Timing
[*] Exaggeration
[*] Solid Drawing (same or different as Weight)
[*] Appeal
[/LIST]

[/LIST]
Think about how to apply all principles listed to each and every stage of your animated scene, no matter how small the stages may be. Make scribbles and thumbnails before posing your rig. Envision and plan. Glen Keane said you should spend half the time thinking about your animation and half the time animating.