A very warm welcome to you, @diavoline! 
Meditating can be tricky for sure- good for you for sticking with it! 
Can you tell what is causing your eyes to want to open? Perhaps there are distractions nearby (sounds, people, etc.) that are keeping you alert. Our bodies will naturally try to address any threat or distraction- so if you are trying to meditate in a noisy, public, or space you feel is unsafe, it is natural that you wouldn’t be able to relax.
Try meditating in a safe spot during a quiet time. Perhaps right before bed when you feel sleepy. If you fall asleep while meditating- no worries! The goal at first is just to get used to the feeling of relaxing and being at ease in your own mind and body 
Meditating is a rewarding but challenging practice, so here are some beginner-friendly guides with tips, advice, and encouragement:
- Meditation Guide
- Meditation Tips
- Finding a Comfortable Meditation Position
- Energy Work: Grounding and Centering
You might also consider the Guided Meditations that can help you to focus. The Tea Meditations and Candle Meditations are wonderful for beginners.
In fact, with tea and meditations and candle meditations, your eyes can stay open and focus on the object of meditation. You might also consider walking meditations or video meditations where you don’t need to keep your eyes closed as well 
Good luck and happy meditating!