So, what does this mean for future legislation in France?

The big question is whether or not Macron is going to uphold the tradition of naming a prime minister elected by the majority faction of the National Assembly. If he does so maybe France will have some social democracy as a treat and recognise the state of Palestine if we're lucky.

He could also not give a fuck as far as I know, French president is a de-jure dictator in the fifth republic's constitution.

He could also resign which would be.... funny I guess?

Or the Presidential race once Macron’s term is up?

Too soon to know about that. Mélenchon could come back or not, if he doesn't nobody knows who would run for LFI. The next mainstream neolib too is unknown. The only certain thing is that we have our Party For Racism that will probably be a threat as usual

not much, the left is not in the majority. This basically means that the president and the PM (nominated by the president according who controls the parliament) the house will probably not agree on anything until the next election. The left coalition can probably form an alliance with Macron's coalition to pass certain legislation which will betray their commitment. Or the President can stall the parliament until the next election and the coalition breaks and eventually loses (IIRC this is what happened last election when France insoumie and the Socialist party "splitted" the vote)