Things that you will need to do for migration from your Magento 1.x to Magento 2.x
1.)Theme Migration: You have to either buy a similar theme if available or else develop your own theme.
2.)Extension Migration: Find if any similar functionality module is availbe for Magento 2.x, if not availabe have to develop it.
3.)Customization Migration: All the customizations that you made again need to rewritten if not compatible if with Magento 2.x, there is a tool for it: https://github.com/magento/code-migration
4.)Data migration: This step involves migrating the database from Magento 1.x to Magento 2.x database. There is a tool for it from Magento 2. It migrates the data into 3 steps: Settings,Data,Delta . (Link for more information:https://devdocs.magento.com/guides/v2.0/migration/migration-tool.html)
You will need a developer or developer's who have atleast few months of experience on Magento 2.