With the Inventory HUD+ mod, you will always see your inventory items during the game. The mod will show all your items, in addition, you can independently customize the mode of the inventory displayed on the screen, for example, make it transparent or change its position from horizontal to vertical. If you go to the main menu, to the Mods section, select Inventory HUD+ and click on the Config button, you can not only customize the display of your inventory but also enable additional functions. One of them is PotionHUD. If you turn it on, then, in addition to your inventory, you will always see what effects are on you at the moment and how long they will last. And if you turn on the ArmorHUD function, then the mod will display information about your armor and equipment, for example, their percentage of durability.
This mod is for Fabric, but you can also download Inventory HUD+ for Forge.