In the absence of a VAT registration number you can apply for a non VAR registered EORI number which I would recommend you to apply for.
Please see the link below:
Get an EORI number
This application is for both when you are VAT registered and when you are not.
If you have to use this non VAT registered EORI number then this will not produce a C79 or a Postponed VAT Accounting statement so I would retain all records you get for the import from your freight agent and use this as a basis for your input tax deduction on the first return.
When you get your VAT Registration number through then please apply for a VAT based EORI and give this to the freight agent to use for future imports.