Lot of freebies are currently claimable on the Fallout 4 Creation Club due to the Fallout 25th Anniversary. Here is a list of all the freebies I found, claim in-game on the main menu. Browse through all the creation club categories, the free items are a bit scattered across them:

Vault Suit Customization

Add the ability to modify the color and number on Vault suits.

Arcade Workshop Pack

Build your own arcade with custom upright arcade cabinets for each holotape game. Also featuring new lighting, posters and flooring options.

Nuka-Cola Collector Workshop

Unlock an all-new house, and a full collection of Nuka-Cola themed workshop items

Modern Furniture Workshop Pack

Give your workshop a contemporary look with over 40 modern furniture and decorative pieces.

Home Decor Workshop Pack

Enjoy over 85 new decorative items for your home featuring new beds, furniture, picture frames, rugs, posters and a new Bobblehead display.

Chinese Stealth Armor & Prototype Gauss Rifle

Chinese Stealth Armor relies on light modulation technology to render its wearer virtually invisible. The Prototype Gauss Rifle uses electromagnetic induction to shoot a projectile at tremendous speed. It is, in essence, a sniper's best friend.