Hi @Anonymous, to be clear, there is no "solution provider" designation. If a partner wants to provide support and not sales they can sell support to existing MS customers. Do you any have further specific questions?
You don't need to transact licenses in order to be a Microsoft Partner. But there are advantages driving and influencing sales of licenses (and Microsoft's different services) as it will a) give you a margin, b) give you better insights in your customers' businesses and c) give you visibility inside Microsoft.
If you 'only' want to support, then I think that you should try to do it 'as a Service' and charge a monthly fee so that you build a recurrent revenue stream. My advise is to craft services so that you deliver from your office instead of sending people out to your clients. By using clever methodology and tools you will be able to create a nice portfolio of Managed Services and that will transform you from being a Systems Integrator to a Managed Services Provider which is a great place to be in terms of profitability, predictability and commcerial value of your business (called 'Enterprise Value').
Thank you @PerWerngren! @Anonymous, to get started as an Indirect Reseller, please see this page: https://partner.microsoft.com/cloud-solution-provider/get-started
If you do not have an MPN ID yet, please see this page: https://partner.microsoft.com/membership
Signing up as a sales partner takes a little bit more (I guess you refer to being a CSP?) than just signing up as being a Microsoft Partner. See signing up as a Microsoft Partner as the entry level. You can also transact licenses just by being a reseller and work with a distributor like TechData or Ingram and that is a great way to start.