Ugs I have just installed Graphene OS on a PIxel 7a and was surpreside to see google play store and services on the device.
You mean the actual Play Store/Services apps available from the GOS App Store? I'm not sure how they were apparently already on a fresh GOS installation, unless you're referring to something other than the actual apps. Perhaps a screenshot can be provided?
package:com.google.android.euiccoverlay
package:com.google.euiccpixel
[...]
package:com.google.android.euicc
package:com.google.android.iwlan
As far as I'm aware, most (all?) of these are system components that you shouldn't be touching.
And how can i fix this, should i install graphene again, if so, how?
You can reinstall the same way you installed in the first place. However without knowing what you mean by Google Play Store / Services, I'm not even sure if there is a problem to fix.