Harry first went around to finding a quiet spot to try out some basic ideas he got from comics, not an easy thing to do as Dudley kept trying to chase him with his gang, leaving very few spots that were available for him. He figured that it had to be in an area that was not too visited by the locals and a place that he could afford to experiment openly which could double as a possible hideaway if the Dursleys decided to get more creative with their punishments without the other adults catching them in the act as it had happened a couple of times. He would find the ideal spot by accident when he was running again from Dudley's gang and accidentally tripped over a rock that sent him careening through a thick bush and through an old pipeline that evidently led to the old wood factory near the waterfront. It was not really a big factory since Privet Drive was a small town, roughly four stories high and about twenty units wide. It had been stripped bare of whatever equipment there used to be with only a few odds and bits left behind and what appeared to be empty offices, but it was still standing with no obvious damage, it was dry and more importantly, it was not used by any squatters or anyone since it had been fenced off after the factory shut down for a better one.
Add in the small storage unit abandoned next to it, and it was perfect for Harry to make it his own secret hideout. Once he cleared out one of the rooms, it was time for him to try out his powers.
His first few attempts to understand his power could be described in two words, embarrassing and frustrating.
Harry would find much of his inspiration to focus his powers from the Star Wars film, specifically the idea of equating his powers to the 'Force' as it seemed to define his powers quite nicely. He had to think very clearly what had happened in the few times something odd happened around him before trying to focus on the memories and the general feelings he would have at those times. It was rather nerve wrecking when he actually felt something react inside him and traveled down his arms to his fingers before something actually happen. He likened the feeling to a small dog eager to please its master, and had to snort at the image of said puppy with its tail wagging and tongue out. It took a while to remember the sensation before he could call upon it at will.
Once he got the feeling going, Harry started to test with the teleporting ability he had the better understanding of. His first test with distance quickly showed that he could get to wherever he wanted in the factory provided he had a clear image of what he wanted without obstructions. Then he tried going to the locations he had been to his entire life, to which he found it quite easy as long as he associated the location with either a person or a feeling of the place. Harry found the latter by accident when he was thinking about the animals at the zoo and found himself near the entrance of said zoo, thankfully with no one witnessing his sudden appearance. He also found that depending on the conditions he could potentially be burnt out from the teleporting, and he needed to be certain that he wanted to move to a spot. Without it, Harry would find his face intimately introduced to the wall or the ground.
Not a nice feeling to have.
Once he got that part down, Harry started trying to emulate the common powers he read from fantasy books and comics, at least those he figured would be the easiest and safest to replicate like creating a ball of light. After all it would be useful to have a source of light when he was in his cupboard, and there was no way it could not be that bad or dangerous right?
Harry found himself rethinking that statement when his third attempt to create a viable light source succeeded in a ball of light the size of a football blinding him by accident, causing him to stumble like a blind man and accidentally hitting his head into the old pipe scaffolding.
After a few minutes Harry would have found most of his sight with a few dark spots obstructing his view and himself reassessing the amount of power he needed to use for the light. With squinted eyes and an image, he tried to make the source smaller with a lower intensity. It would take the better part of the hour and additional blinding to finally get the glowing globe to be the size of a golf ball with enough light to help him read comfortably in the dark. That session also left him drained enough to stop for the day, but that did not diminish the sense of accomplishment he had gotten from the test.
Another power he tried to emulate was the ability to conjure fireballs, admittedly an idea that came from his childish desire to act out like the wizards from the fantasy books. Harry chose the old incinerator left in the factory with the reasoning that if he accidentally did it too aggressively, he could contain it without it burning the place down. His first few attempts were quite pathetic, merely creating enough sparks to perhaps set dried tinder on fire but not an actual fireball. Around the second hour mark and after the thirty-first attempt, Harry was annoyed enough from his lack of progress that he basically threw both hands at the incinerator and just yelled in frustration. That frustrated yell became a surprised yelp as the incinerator practically exploded into flames, the heat from the flames forcing him back a few feet instinctively to avoid getting burnt.