I want to connect my phone or laptop to the Speakers and listen to music
Speakerwise I would take Adam Audio since I know them and they are good imho.
For connection do I need a Bluetooth “Reciever” (DAC I guess ^^)
Does the Fiio BTR something something work?
Can you recommend me a setup?
I would also love to use the BT for a portable solution (I got wired headphones I want to listen to it while I go outside)
Anyone can help me what to buy?
Spakerwise I would also go for Micca but they’re not available in Germany.
I would love some small speakers.
I think your best bet for speakers is to just search for powered speakers with bluetooth. Crutchfield has a bunch to give you some ideas. For the headphone the Fiio bluetooth receiver worked just fine for me and it sounded nice. You could also get a dongle to attach to your phone and plug the headphones into that.
Smallest one and cheapest I am aware of is the AIYIMA S400 which has BT and is active, so thats all you need to buy. https://www.aliexpress.com/item/1005006578161841.html
They have a warehouse in Germany so shipping will be really fast for you.