What is the total size of BTC core, because its very slow to download
if you have problem downloading the blockchain, you can download the bootstrap torrent file from bitcoin.org
here is the link:
https://bitcoin.org/en/download at the bottom of the page
that is the best hint for any newbie in my opinion. Download bitcoin history quicker from a torrent, then update the reminder and you are ready to go.
Size of the blockchain is huge, but it will grow slower than the capacity of the hard disks. Nothing to worry.