It shows promise on your part. Here's some things you can do to improve your technique:
1)Hold off on the captions. Give the reader credit to follow what's going on. Captions detract from the quality and/or funniness in comics in most cases.
2)You don't have to follow-up your punchline with filler. It's not necessary or prudent to have every dialogue space filled if you don't need it.
3)Try experimenting with the divider backgrounds, they'll help you to avoid situations where you have to run over on two dialogue boxes for one character.
Other than that, I'd say you should do just fine here.
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If you do just one thing in life, then you need to get out more and expand your horizons. Honestly, that one thing can't possibly take-up all your time.