I hope you got tickets to see the film, because it is epic! This movie was the perfect bookend to an incredible saga of movies. Even at three hours long, I would suggest multiple viewings to fully absorb everything going on in the movie. You will also need to buy multiple sets of this Minimates release from Diamond Select Toys to get everything you need to assemble your team of Avengers.
In comic and specialty shops now is a special four-pack featuring Tony Stark in his Quantum suit, with alternate heads for Hawkeye and Ant-Man; Black Widow with an alternate head for Nebula; Quantum Suit Hulk and Quantum Suit War Machine. You will need two sets to get enough bodies for Hawkeye and Ant-man.
Walgreens also has four two-packs available, pairing  two cast members from the sure-to-be-blockbuster film – Iron Man with Thanos, Black Widow with Hawkeye, Hulk with War Machine, and Quantum Suit Captain America with Quantum Suit Rocket. That last pack also includes alternate parts to turn Captain America into Thor, complete with Stormbreaker!
These sets all look great and will go great with your MCU Minimates collection. Head to your local retailer now to pick these up.