The history of Wakanda can be found here: https://marvel.fandom.com/wiki/Wakandan_History
To those who have a reason to know it, this can be considered accurate up to the section titled 'T'Challa's reign' with the following alteration in the WWII section: "No Allied forces entered Wakanda. After the Wakandans defeated Klaue, T'Chaka and a small force left Wakanda and fought the Nazis in Northern Africa, knowing they had to be stopped or they'd be invading Wakanda again." (Those who were alive and fought during WWII could have met T'Chaka there.) The first sentence of S'Yan's Regency is also correct: "After T'Chaka's death S'Yan ascended to the throne and became Black Panther. S'Yan merely served as regent until 13 year old T'Challa was old enough to claim the throne." (T'Challa's history from there is left up to the person who apps him.)
What is known about Wakanda: It is a relatively poor country in northeast Africa with an agrarian society. If SHIELD knows better, they aren't saying. (SHIELD does know better though not the full truth; the Nazis knew better and some of their classified files on the country were recovered by the SSR and ended up as part of SHIELD.)
Politics: Wakanda has always been isolationist. That is still mostly true though it has been changing. There is an Ambassador to the UN. There is a Wakandan embassy in NYC, left over from when the UN was there. Though damaged in 2014, it's been repaired and is still in use.
Trade: Wakanda maintains the appearance of being mostly self sufficient though they do import some items. Their chief export is wheat. Through covert agents and middlemen, they sell a small amount of vibranium gain foreign currency used to buy things they don't want the world to know they have a use for.
Tourism: None.