Read a few articles in reputable science journals and you will get the jist:
Mutations of viruses happen all the time and they are expected.
They are caused by errors during the virus replication process.
Sometimes the mutation becomes more virulent, meaning it is easier to infect a new host. Sometimes not.
Often the mutation is of minor consequence.
Only testing and data will determine what, if any changes are expected from the mutation.
Sauce: https://www.science.org/content/article/pandemic-virus-slowly-mutating-it-getting-more-dangerous