Visit the official Adobe website. Avoid third-party "crack" sites as these often contain malware and lack critical security updates.
Laptops often throttle the CPU and GPU when running on battery to save power. Always edit while plugged into a wall outlet.
Select a subscription plan. You can choose the standalone Premiere Pro plan or the "All Apps" bundle if you also need Photoshop or After Effects. Sign in or create an Adobe ID. Download the Creative Cloud Desktop installer. Open the Creative Cloud app and sign in.