The US Space is only a year old so it hasn’t gotten around to issuing much in the form of regulations or guidance yet, but it has issued guidance on how to wear the Operational Camouflage Pattern uniform, aka the ACU.

Space Force Guidance Memorandum 2020-36-01 published late last month spells it out. Although there aren’t many enlisted in the fledgling service yet, they’ve already started deploying space support teams to ongoing operations, taking over the role long filled by USAF Space Professionals.
As far as insignia goes, the minimum configuration consists of a full-color US flag patch, grade insignia, occupational badge, and name and service tapes with space blue embroidery on three-color OCP background. Insignia can be sewn on or Velcro, but it all must be the same.
USSF occupational badges are mandatory, but sister revive badges are optional. However, only two can be worn at a time.
The full-color US flag will be worn on the left sleeve, “centered at the top of the velcro, and worn unless deployed to a contingency operation that aligns under separate/independent OCP wear guidance.”
A higher headquarters patch is required to be worn centered below the flag patch on the left. Spice brown subdued patches are authorized until space blue patches are available. The assigned unit patch is required to be worn centered on the velcro patch of the right sleeve.
Space Professionals will wear velcro or sewn-on space blue name tapes on the back of their patrol caps, and officers will also wear rank insignia on the front.
No word on the configuration of enlisted ranks yet, as the service is waiting to see whether they’ll be forced to use naval ranks. But my money is on USAF-style stripes with the star replaced with the Space Force Delta like CMSgt Roger A Towberman is wearing in his official photo as Senior Enlisted Advisor of the United States Space Force.

Regardless, there’s a grace period until April 1, 2021, for members to update their uniforms to the Space Force-specific configuration. Former Airmen may also continue to wear ABUs until 1 April.