Shields do not require proficiency to use and take up a hand equipment slot. Equipping and unequipping a shield takes an interaction just like a weapon.

Shield- 10 Currency - Common

Increases Armor Class by +2

 When you have this shield equipped, you have advantage on saving throws on incoming area of effect or radius based attacks

Variants: Wooden Shield, Metal Shield

Simple Covering - 5 Currency - Common

Increase Armor Class By +1

When you go to equip this shield, you can choose to have it take up an arm equipment slot instead of a hand equipment slot. If you attempt to equip another shield in any way you gain disadvantage on all attack rolls.

Variants: Cape, Long Shirt Sleeve

Improvised Shield  - 1 Currency - Common

Increase Armor Class By +1

 When you have this shield equipped, you have advantage on saving throws on incoming area of effect or radius based attacks

Variants: Pot lit, Sewer Grate

Buckler Shield - 25 Currency - Common

Increase Armor Class By +2

 When you go to equip this shield, you can choose to have it take up an arm equipment slot instead of a hand equipment slot. If you attempt to equip another shield in any way you gain disadvantage on all attack rolls.

Variants: Small Shield, Armed Combat Shield

Armor Shield - 25 Currency - Common

Increase Armor Class By +3, however your walking speed decreases by 5ft. 

 When equipped, when making a blocking save against an area of effect or radius effect, add the shield armor class bonus to the total roll.

Variants: Templar Shield, Metal Shield

Tower Shield - 75 Currency - Common

Increase Armor Class by +5, however your walking speed decreases by 10ft

 When equipped, when making a blocking save against an area of effect or radius effect, add the shield armor class bonus to the total roll.

Variants: Titan Shield, Reinforced Shield