Napoleon has quite a story! Came from Corsica, ended up leading French armies at a very young age and when he became a general, he quickly attempted a coup, relying on his military supporters and taking advantage of the political turmoils in France during the Revolutionary Wars.

Napoleon eventually became Emperor - the first Emperor of France, which was known to be a thousand year old kingdom. He then declared major wars in Europe for about 10 years, resulting in 6 different coalitions, the last one eventually succeeding with France's defeat in Russia and at the battle of Leipzig in 1814 (the battle of Waterloo in 1815 could never have been won, and France was already at a huge disadvantage at that point).

So what did he try to achieve? Many things. Nationally, he had tremendous support from the French people and set up many legal and political entities that are still the roots of not only French, but other countries' legal systems - notably the "Code Civil". He also created territorial policies. All this without threatening legitimate opposition during his reign - even from the royalists. He basically tried setting up a legacy of French Emperors who would sit at the top of Europe's power hierarchy.

This brings us to foreign policy. Until before the Napoleonic wars, France and England were huge rivals because of their respective colonial empires. Only 30 years had passed since the American War of Independence. Not only that, but with the fall of royalty, the newly formed French Republic had very serious diplomatic issues with neighbouring Kingdoms - particularly Austria.

Napoleon therefore decided to take Europe by storm. While being a unique and amazing general and often depicted as such, he had a broader strategy in mind. First, he aimed at dampening English influence in European affairs. He also wanted the HRE dismantled and in fine, totally shift the Balance of Power on the continent in France's favour. During the 1802-1810 years, France kept creating vassal states, annexing nearby provinces, breaking rival armies... Europe had a long tradition of Balance of Power, with each state hoping to maintain it. Indeed, having one state that would be much stronger and dominant over the others in such a short span of time was threatening as it could get out of control. Making France out of control for other countries was Napoleon's gambit - very comparable to Hitler's gambit in that regard.

"War is a strange art. I have fought a hundred battles and haven't learned a thing that I already knew during the first one."

TL;DR: Napoleon's goals were to achieve French dominance in Europe, through innovative internal policies and aggressive diplomatic means (coercion, war...).