To create your Smart Contracts in the Ethereum network you will need a way to interact with Decentralized Applications (dApps) from your browser.
The most well-known browser extension is Metamask
Available for Chrome and Brave
What is Metamask?
If you are new to Ethereum or Metamask please take a look at this article
Get some ether
Once you have Metamask installed in your Chrome or Brave browser you will need to get some Ether to deploy your contract and pay the gas fee of your transaction
How to get Ether for test and mainnet