A fascination with history is good! I'm not entirely sure why people are downvoting.
The only thing that I would suggest is learning about "historiography". As that's very important when you are learning about "contested" or "active" fields of historical research.
History is always biased, and often is used as a way to frame the present, more than it is the past.
to your point, Learning about the history of the empire is currently difficult for a number of reasons:
1) certain parts of the world are deeply ashamed of it, and will readily believe the worst, even if its logically not actually true.
2) other parts truly believe it was the best thing since sliced bread and civilised the world.
the truth lies in between.
Because the empire is now partly wrapped up in a culture war (renaming of streets, statues etc) internet and popculture sources for history tend to be either hyperbolic or really black and white.
For example "England was the real empire builder and Scotland were also victims and were not really involved." This is patent bollocks for a number of reasons not least of which Scotland had a much higher rate of literacy and numeracy, so were needed to actually run the empire. However this view as scotland being the Victim of Englands bloodthirsty slave trade, is a device that is (mostly unwittingly) used to further the othering of the UK to allow for scots independence.
This is where historiography comes in, an academic or, group of people will set out with a new narrative (Scots were the victims of empire) and start searching for sources to back that up. They will write a set of papers that will put forward the narrative. It will be challenged by others and perhaps it will shift accepted opinion on the matter.
Another example is "Britain stood alone against the germans in WWII and won the war". was very fashionable up until recently. Now people are pointing out that it had the biggest economy by far, and it's empire covered large parts of the planet. It wasn't one island, it was an entire empire. More over, it almost single handedly funded the American industrialisation that kickstarted the post war American boom.
Keep looking, keep questioning sources and motivations (including mine.)