Im practicing with smart contracts development with Truffle and im curious to know if its necessary to keep the "Migrations.sol" file with the "1_initial_migration.js". Its good to keep this files even if you have already done your own solidity file?
Migrations are a way to automate and manage the deployment of smart-contracts on different networks. You can write javascript files to automate the deployment of several contracts. The migration.sol contract stores the prefix of the last migration file that was executed. It is useful if you need to deploy and manage complex systems with multiple contracts. If you don't use this feature of Truffle, you can safely delete both files.
Please consult the official Truffle documentation here for additional details.