Easiest cheapest way to fix dent

I am trying to fix a small dent... well multiple small dents on the cheap. Example below. My plan is to use the original faded paint on the barracuda as the primer coat sand with some fine grit and do some minor bondo work on door dings ect. Then I plan on spray painting with rattle cans with a 2X rustoleum paint primer and paint included. I am choosing a brighter color close to a B3 blue. My question is what are some simple steps to make sure bondo sticks to these small dents/dings?

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