While the default rules for lifting and carrying are intentionally simple, Encumbrance offers a variant if you are looking for more detailed rules for determining how a character is hindered by the weight of equipment. When you use this variant, ignore the Strength column of the Armor table in Equipment Section.
To refresh, as stated under the Strength Ability score, Strength also determines how much weight you can lift, carry, and drag.
If you carry weight in excess of 5 times your Strength score, you gain the encumbered condition, which means your speed drops by 10 feet.
If a creature is carrying weight in excess of 10 times its Strength score, up to a creature's maximum carrying capacity, the creature is instead heavily encumbered, which means its speed drops by 20 feet and has disadvantage on ability checks, attack rolls, and saving throws that use Strength, Dexterity, or Constitution.
All penalties also apply when you are attempting to push or drag large amounts of weight.