Really depends on what micro service you are offering.
When you say "For every micro service there is backend", it is confusing as micro-services are backend services.
Your front end can be as simple as the AWS console. Get your users signed up and offer your services as an API or via a shell or however you were planning to give them.
For scaling, try using containers. Though it should not be a problem when you are starting out, you could just use a single large instance and take it from there.