Good luck and take care.
Before we talk about how to stop it. We should agree first, never hate wandering mind. Because this one is natural habit of ours. Never think wandering mind is a big problem.
This mindset will help u understand more about your mind. Open with every mind condition. And not getting more worry and frustation.
Dont worry with wandering mind.
If u can accept this. Then, u can try this method.
First, for most of people meditation is about preparation. make your self relax. Take a nice place to meditate. Prepare your environment. Prepare your seat.
Second, trying to relax. U can Listen some soft music for 5-10 min . If u dont like music, Pray or chants for 5 minuites also can help u.
Third, empty your mind. let your mind wandering. If u doing breath meditation method. Slowly try to focus to feel your breath. Never want control your mind breath. just see what happend without interupt the process.
Until at some point u feel more relax and can more focus with breath. Keep meditate.
Hope this will help u