Web3js – How to Use Specific Version of Web3

I have listed the versions of web3 versions installed in my system

 npm ls web3
        inbox@1.0.0 /home/mdvenkatesh/Desktop/etherium solidity programes/inbox
        +-- truffle-hdwallet-provider@0.0.6
        | `-- web3@0.18.4 
        `-- web3@1.0.0-beta.26 

In my code i am using async await. i want to compile my code and run

But i am getting error

accounts = await web3.eth.getAccounts();
           ^^^^^

SyntaxError: await is only valid in async function

1) How to use version 1 without uninstalling the previous version of web3

2)In My previous projects i am using promise's if i uninstall the old version will it effect my previous code while compiling

3) I tried to remove using npm but showing me error

npm remove web3@0.18.4
npm WARN truffle-hdwallet-provider@0.0.6 requires a peer of truffle@4.x but none is installed. You must install peer dependencies yourself.
npm WARN inbox@1.0.0 No description
npm WARN inbox@1.0.0 No repository field.