replied in your other thread Jules
hi there and welcome to the forum and to tropical fishkeeping.
there's a critical problem there to start off work, frogs are freshwater, clownfish are marine (saltwater) fish. They're very different and there's abs9olutley no way you can have both in the same tank.
I'd advise you to stick to freshwater tropicals to start off with, the saltwater is a lot more money and a lot of work, it can be done by beginners but it's generally best to start out with trops which are a bit easier then you can get a marine tank once you've a bit more experience.
The 10l tank is really very very small, there's not a lot of fish which are suitable for it, also very small tanks are very unstable so they're hard work to look after. However that being said the tank would be OK for a single dwarf frog if you really want to keep one. But If you want more variety and a community tank you should be looking at something quite a bit bigger. 100litres is a good size to start off with, easy to manage and with enough room to get a good variety of fish.
You'll need to cycle the tank before adding any fish, there's two links in my sig 'what's cycling' and 'fishless cycling' those will explain the process to you and what you need to do. Have a read of them and then ask us any specific questions you have.