[SaS TrooP]

OK, so about these 2 engagements:
Battle of Dakar occurred in September 1940 and was mainly naval engagement. In short, Franco-british navy conducted show of power near the shores of Dakar, Senegal. Its purpose was to persuade French West Africa to join the struggle for De Gaulle. But Vichy authorities were not amused and sent in their own naval batteries, aircraft and nearby task force (with battleship in it). The battle went extremely unfavourably for the Allies and humiliated them, after entire task force (including aircraft carrier and battleship) were damaged and out of war for several months.
As of land engagements, there was just one: FF forces tried to conduct a beach landing near Dakar in order to advance on foot, but it failed under heavy fog and generally bad weather conditions. If FF forces set ashore is unclear to me. They could not even land or eventually land and leave before making a contact.
So in this case - if you want to handle this one - we could assume landing has occurred and then it was revoked, after light combat. I would have to be very careful with casualties, but Vichy forces should not be powerful.

The other battle, Gabon, is much more important from our point of view.
In Gabon it went fair better. That was November 1940. French forces blocked weak Vichy navy in the vicinity of Port Gabon and landed its forces there. Main area of the fighting was airport at Libreville (I call it airport, but historians use "aerodome" what probably indicates its small size). There were heavy fighting for it for 2 days, but with british light aircraft help French managed to capture it. Then, after brief combat Libreville was captured and this turned French Equatorial Africa and Chad into de Gaulle's men.

Later, French forces will be reorganized in Eritrea into 1st Brigade of the Orient and will take part in battle of Keren against Italy. This - I believe - should be depicted quite carefully as fighting there was extremely bloody. And then Operation Exporter, an invasion of Vichy Syrian and Lebanon, that finally provided de Gaulle with resources and manpower to create first Free French Division.
Rest of the story will follow up.