At this time of year you can start trimming off dead leaves and stems from last year. As you probably don't know what sort of plants are in the garden I would suggest that you only tidy up the plants. Take photos as they sprout/flower and post them on here as questions and we can identify them ( we like this type of question!!). Take note of where the sun shines and where there is shade in the garden, use a compas to get the n/s/e/west orientation. Either ask on GOY or at a good local nursery for plants for these areas to fill in empty spaces. Be aware that most herbaceous plants (these die down in winter) will not be showing above ground yet.
Go to the library and start borrowing some gardening books to read/look at the pictures.
What fun to be a new gardener, enjoy yourself!!

Hi New gardener and welcome to GoY. Is there any chance you could add a photo or two of your garden to your question? I'm intrigued by your 'stones' and a photo will give a good idea of why they are there. Other than that I second Volunteer's suggestions... definitely do not remove any plants yet unless you know for certain they are annuals, which is unlikely I think :-)

I almost envy you just coming to gardening a whole new world to explore. Ask lots of questions and, as well as visiting your local library to look for gardening books to read, visit second hand book shops and charity shops - it is amazing what you can turn up!

Hello Anew!

Look forward to seeing some pics of your garden. Maybe you can write a blog? While planning you can make a list of your likes and dislikes in gardens - colour, types of plant etc. Perhaps you've seen some gorgeous ideas or plants that you could replicate.
You can ask as many questions as you like on here, and Moong is right, a photo or two will really help us answer you.

Happy gardening,
weeding x