Right now I have an MVP of a function as a service platform; a general purpose development tool. I'm thinking meetups are the best bet, just to meet people, ask questions, and listen to pain points. But that alone is a skill set that needs to be cultivated; asking the right questions, not coming off as pushy, being self confident, and finding the right events.
The nice thing is that presentations shine a spotlight on you, and then potential customers will come to you rather than you having to go to them. Eventually you will need to do the latter, but your first customers are likely to be people in the crowd watching your presentations or their friends. When you do start having to go find more customers, you will have a much better idea who to target as well and have at least a small network to utilize.
Then you have a different problem - you don't have a way to reach target customers.
Even if you build your product, how are you going to build a sales pipeline? Your customers won't hear about your product by themselves - you have to get it to them. Many many companies make products that are good, are actually useful, but they don't know how to build the marketing/sales pipeline that will actually make their products profitable.
And just like validating the product to build - building/validating a sales strategy is usually something you should do before building the product, both because it's harder, and because findings there may change what product you end up building.