hi sven
welcome to the site to start with, you have come to the right place to start your journey!
mate the best advice I can offer is get yourself some books, read as much as you can, if possible join a club, you should be able ot find some around the joint, these are a great place to start as you will have people new to bonsai and experienced alike! ask as many questions as you can, we have a new wiki feature here which is a great resource.
your setting is a great little start, I think there are some things that can be improved on but that will happen in good time. I am a little concerned about one or two of the trees you have there, I hope they are yellow due to shock or cold but this can happen. aesthetically I think the image is a little 2d if that makes sense, to create depth you need to place the trees not in a line but forward and back of the centre of the pot line.
otherwise you have a great start. buxus can be a little brittle but wiring is possible, between that and some selective pruning you should get some nice little trees. also if possible try and find some that are different in height and trunk thickness this will help with the flow of the setting
good luck and keep us posted
jamie
