The "w" and "v" consonants are sometimes tricky for non-native English speakers. Depending on your native language, age of exposure to English and self-awareness, the "w" and "v" may be interchanged or sound like a mix of the two. Native speakers of Punjabi and Russian for example may find this to be difficult.
Let's try a simple test.
Go to a family member or close friend. Say the following words one after the other in the following order.
Why Vie Wax Vax Vicks Wicks
Ask whether the "w" or the "v" came first. If there is any hesitation in their response, then it may be helpful to look into this a bit more seriously. The two sounds are very different and are produced differently so the sounds should be easily distinguished.
Take a look at the link below to get some quick tips and word lists to practice. I've included sentences and tongue twisters for you to challenge yourselves.
Once you are a bit more confident, start paying attention when you speak in conversation. It may be easy to do when reading or practicing by yourself, but you might forget these rules when public speaking.