Looks like your old solenoid is attached to some sort of adapter, rain bird from the looks of it, can you take a picture of your old valve to confirm?
If you already have a replacement orbit solenoid, you could try unscrewing the adapter from the old solenoid to use with the new. Specifically, this is the part that looks like an adapter:
Hold on to it, and turn the solenoid counter clockwise to separate the two.
Otherwise try the rain bird solenoid:
https://www.homedepot.com/p/100563755