“the Scottish pound or the Euro umm.”
There is no such thing as the “Scottish Pound”. Banknotes issued by Scottish banks represent Sterling Pounds. The Bank of England is the central bank for that currency and it holds the monopoly for issuing sterling banknotes in England and Wales and regulates the issuing of Scottish banknotes by the banks it authorises to do so. Such notes are not Legal Tender but are always accepted in Scotland and are widely accepted in the rest of the UK.
There is nothing to stop Scotland using any currency it wishes if and when it becomes an independent nation. It has no chance of creating its own currency (or at least one which will be exchangeable outside Scotland). Furthermore, should it join the EU it will have to pledge to adopt the euro (there is no “opt-out” for new members). Scotland has two problems on this front: (a) it is unlikely to be accepted for membership as it does not meet the economic criteria and (b) (which will probably impinge on (a) its economy does not qualify it for euro membership. But there is nothing to stop it using euros or dollars (though what they might buy them with is perhaps something Ms Sturgeon is not sharing with her voters just for the moment).