Generally speaking, in the UK I would recommend checking out Superdrug, as all their own brand products are cruelty-free and often vegan as well. Boots Botanics skincare range is also worth having a look at, as they are cruelty-free and mostly vegan. Also Sainsbury offers a lot of cheap options of their own brand, which is BUAV approved. Holland & Barret will be a good source for your needs too. In German drugstores you can find Alverde, Alterra and Terra Naturi, which also offer a lot of vegan products. Check their websites to find out more.
If you are a bit more adventurous and want to have a look online for alternatives, check out my Pinterest board below to get some ideas. Just as a disclaimer: I try to update these boards as often as possible, but I cannot guarantee that all the information are correct. It is always important that you do your own research as well! Some of my personal favourites are Urban Veda, Pure Chimp and Love the Planet.
There are plenty of haircare products out there for your to try. One of my favourite high end products are by Paul Mitchell, but I have tried plenty of cheaper products form the drugstore that had good quality. I really liked the Australian Organics I found at Holland & Barret as well as some cheaper ones by Superdrug.
There are also options for colouring your hair, and it does not have to be Henna if that is not for you. For us lot that loves colourful hair, check our Directions or Manic Panic. Superdrug has a great range of dying products as well.