Though am a beginner and I found this forum interested,and I believe that it's the best platform for me,and I still don't understand the modes of operations and ethics and kind of investment on this platform.
You should know you can't invest in the forum, because it's called Bitcointalk those not mean you can purchase bitcoin here, and anybody that private chat you to help you invest in bitcoin is definitely trying to scam you, so you should ignore any message received.
Before you should invest in bitcoin, you should have basic knowledge of bitcoin and cryptocurrency, you shouldn't just invest because you see other people investing, don't just follow people and invest blindly.
After learning the necessary things you should know about bitcoin and cryptocurrency, I think you should just buy bitcoin, transfer from exchange wallet address to your non custodial wallet address and hold.