This is the webcam I have, and it's quite common among streamers: https://www.amazon.de/Logitech-C920-HD-Pro-Webcam-Videogespräche-Videoaufnahmen-Full-HD-Stereo-Mikrofonen/dp/B006A2Q81M
This is the mic I have: https://www.amazon.de/Samson-SAC01UPRO-C01UPRO-USB-Mikrofon/dp/B00HXE4BYW
I think this is the most popular streaming mic: https://www.amazon.de/Blue-Yeti-USB-Mikrofon-Silber/dp/B002VA464S/
Also, having at least 2 screens can be useful for streaming, that way you can always have your streaming software and chat visible on the side. You can find screens for €200 that are good enough as a second monitor.
If you want a new pc, for streaming poker you don't need much in terms of pc hardware. For example this pc is already a lot better than what I currently have, and would even be good enough for streaming a lot of games: https://www.amazon.de/Megaport-Gaming-PC-Vollausstattung-FX-8300-Computer/dp/B00HVB8KB2/
If you buy that pc, cam, mic and two €200 screens, you have a very decent brand new setup for roughly €1200. But to start out, just buy a cam and mic first, install OBS on you current computer and make a test recording to see how it runs. That's how I started, it cost me less than €200.