Use a VPN service with a proven track record to connect to a seedbox paid for with crypto, and download only from top-level private trackers. It's about as secure as you can get as a casual user.
In reality, though, a simple VPN is probably enough. Maybe not even that if you're in a country that doesn't give a shit.
Uploaders and users with higher user classes get invites. You also get some minor perks if you donate, one of which is one invite. It's $10 to get access to those perks. So technically, you could send a friend 10 bucks and he could invite you in.
I don't think I've ever seen this forum mentioned on any recruitment thread like you would with private trackers, so a direct contact is probably the only way in. They've done a pretty good job at staying out of the spotlight since the domain change. It's a pretty underrated place.