@Lebzanwa I'm afraid that this kind of actions is not really Saleor-related, and we cannot help you as good as some other communities which are oriented for your specific operating system.
@yogesh-kamble You could create a collection for products specific to some brand, or if they're within one category - enter the category, filter the results, copy the URL with filtering entered and paste it into the MenuItem as custom url.
@mfcovington We were planning to integrate Avalara but as far as I'm concerned it's postponed now. We have a vatlayer support which handles only European countries. If you mind handling this, we would offer you our full support throughout the development.