I am the director of a UK Limited Company and use this to run a
website selling electrical goods mainly in the UK, but also in Europe.

I now wish to sell similar goods in the USA via a similar website that
I am in the process of setting up. The goods will be dropshipped by US
suppliers.

Most US suppliers want to see a business permit, trading license, etc,
before they will supply me with these goods. Is this a legal
requirement? It could be seen in either of two ways. Firstly that US
consumers are purchases goods from a UK company, so I don't need a
permit or license for the US. Secondly, I am actively selling in the
US, so do need a permit.

Also, what is the tax position? Do I need to collect US sales tax? Do
I have to pay US corporation tax or personal tax?

What I need is a comprehensive answer of what I actually needto do to
start selling goods in the US and where I am liable for tax.