How do I find my new portfolio beta?

I'm looking to calculate the beta of my new portfolio, but I'm unsure of how to go about it. Can you walk me through the steps I need to take to find my portfolio's beta? I've heard it's an important measure of risk and I want to make sure I'm properly assessing the potential volatility of my investments. Should I be using a specific formula or software tool? Additionally, what factors should I consider when interpreting the resulting beta value?