This seems very last minute - April to June?
And the Adventurers’ League infrastructure has atrophied, at least in my area, due to the lack of AL coordinators. Plus turning over official content creation to third parties like Baldman and GameHole.
Most of the former AL DMs I know have either...
I’d check out Free League’s 5e-based Lord of the Ring’s Role-Playing Game. (The new edition of Adventures in Middle Earth). It blends 5e and Middle Earth very well.
Website here.
All these AL adventures have five 1-hour mini-missions, that are good for a short time time slot and for beginning DMs:
DDEX1-1 Defiance in Phlan
DDEX2-1 City of Danger
DDEX3-1 Harried in Hillsfar
DDAL04-1 Suits of the Mists
DDAL05-1 Treasures of the Broken Hoard
DDAL07-01 A City on the Edge...
If you’re a Luddite, maybe Owlbear Rodeo? Won’t give a lot of functionality, but does the basic job of tokens on a map very well. And is free. Neither Foundry or Fantasy Grounds are easy to learn, and while playing in Roll20 has a low barrier to entry, DMing does not.