Ymir, at this point in time and considering you are just beginning to get acquainted with straight razor shaving my suggestion would be to give no thought at all to pastes as yet.
Get used to your new SRD strop with the secondary strop it comes with. That combination will allow you to have edges that
will be very shaveable. Hand rub your strop leather several times a day and everything will fall into place for you.
Starting out it just makes more sense to forget about pastes, sprays and such.
Master the art of stropping and you will then find yourself comfortable to begin and read and understand what each kind of
strop additive can do to help you. Take your time.