Can I do that with that?
Takes some time before importing your private key to any new wallet you are going to use to ensure you have installed and set it up safely and correctly. As mentioned above, you can import your private key to Electrum (or any other wallet) just as you imported it to Blockchain.com, but since that key is now stored on Blockchain.com's servers it will never be truly safe again. Once you have spent the funds from it to the 8 addresses that you are planning, you would do well to safely set up a brand new non-web wallet.
If you do choose to use Electrum, you should only ever download Electrum from the official site here: https://electrum.org/#download
You should verify your download prior to installing for extra safety by following the guide here: https://bitcoinelectrum.com/how-to-verify-your-electrum-download/