Can someone help me with this skript:

[Spicykonrad]

command /cowset:
    permission: mobspawn.use
    permission message: &cNo.
    trigger:
        set {cowlocation} to player's location
every 10 seconds:
    spawn 1 cow named "&fCow" at {cowlocation} <--- this line does not work

[Enchanted_Reeses]

command /cowset:
    permission: mobspawn.use
    permission message: &cNo.
    trigger:
        set {cowlocation} to player's location
every 10 seconds:
    spawn 1 cow at {cowlocation}
    set name of last spawned entity to "&7Cow"

you must set the name of the entity after it has spawned, so this should work
it is tested!