How to store arbitrary data in the bitcoin blockchain and how can I differentiate between a transaction an those data?
Have a look to these data sources:


https://bitcointalk.org/index.php?topic=1023190
https://github.com/petertodd/python-bitcoinlib/blob/master/examples/publish-text.py


And of course the "modern" (and cheapest) way is storing arbitrary data in segwit part of transactions. I do not know is there ready tool for it, but it is not very difficult to write it.


  Is there a newer website/service that supports me putting data into the blockchain? 


https://cryptograffiti.info/ (based on bitcoin cash blockchain)