If you are able to buy things online, just google rosary beads and you’ll have dozens of sites pop up that sell rosaries. They are cheap or they can be expensive, depending on the style you choose. Just buy from a reputable site and it should be fine. Otherwise, you can shop any Catholic store in your area (if there is one). Some Christians stores carry a small section of Rosary beads but it depends on the store. In my area (San Diego) there are a couple of Churches that actually have gift shops.
Of course, non-Catholics can pray the Rosary! It is a beautiful meditative prayer. 18 of the 20 mysteries are directly about Jesus and you should have no problem contemplating them as a Christian–except maybe the 5th luminous mystery which is the institution of the Eucharist. If you do not believe in the Eucharist (called the source and summit of the Catholic faith) then you can meditate on the Last Supper, what it means to you, what the Scriptures say about it, and even call on God to open your mind to this mystery. The other mysteries are about what Jesus did for Mary. They are the 4th and 5th of the Glorious Mysteries- the Assumption of Mary and the Coronation of Mary. If, as a non-Catholic, you are not ready to accept those teachings as truth, then I would just recommend meditation on the other Glorious mysteries. Or you can simply meditate on Mary’s example of faith for all Christians, her role as Jesus’s Mother, etc.
Praying the Rosary is often awkward, at first, if you are not used to praying in this way. But keep at it and I assure you it will draw you closer to Jesus. Though it is often accused of being a rote prayer, it is NOT! Because you are contemplating the mysteries while saying the words of prayers you are actually able to discover new things you never thought of before with each mystery.
I hope this helps!
