What does the padlock mean on the top left of my address bar? Is that the same as buying a proxy VPN?

Assuming you mean the green padlock that chrome has towards the left, that just means that you're accessing the site over https, and that the website's certificate is valid.

Green padlock does not guarantee that the content of the website will be safe to you. Even phishing sites can have a valid certificate (and show green padlock)

VPNs/proxies are not the same as the green padlock. You are not anonymous to do whatever you want just because the padlock exists. VPNs allow you to send your traffic through it so instead of [you] -> [website] it becomes [you] -> [vpn] -> [website] so the website sees the vpn's IP instead of yours.

/r/hacking Thread