128GB internal storage isn't the largest on the market but should do fine for most people. It supports memory cards of the microSD type.
From Amazon
Samsung Galaxy A71 Mobile Phone; Sim Free Smartphone - Prism Crush Black, (UK Version)
OnBuy
Samsung Galaxy A71 128GB Smartphone Black -
Major Mobiles
Samsung Galaxy A71 SIM Unlocked (Brand New), Prism Crush Black / 128GB