Premiere Pro is a very resource-demanding software. Here are a few ways you can improve the render speed. You can find all tips in this video
Update Premiere to CC23
Motion Graphics templates from After Effects now render 2x faster in Premiere Pro thanks to Multi-Frame Rendering. Depending on the template and your system you may see even more significant speed gains.
Enable GPU acceleration
Click File – Project Settings – General and select “Mercury Playback Engine GPU Acceleration (OpenCL)” for macOS and “Mercury Playback Engine GPU Acceleration (CUDA)” for Windows.
Media cache clean up
Go to Premiere Pro – Preferences – Media Cache on macOS or Edit – Preferences – Media Cache on Windows, and click Delete unused.
Pro tip: set a cache folder to an SSD hard drive rather than a regular HDD drive (click Browse and select a folder on your SSD hard drive). It will speed up the performance dramatically.
Change the resolution quality
Mute all effects
Click on the effect button.
If you don’t see it drag the effect button to the toolbar.
Select all heavy videos in the project, right-click – Proxy – Create Proxies… – OK
Once the media encoder rendered footages, toggle the proxy.
If you don’t see this button, drag it from the toolbox.
Import pre-renders instead of MOGRTs
Right-click on the animation – Import as video. The Pack Manager will import a video file instead of a MOGRT. It will help you speed up the project and rendering. The animation will not be as flexible as the MOGRT file but it will be much faster. Please note this option is not available for all animations. It will be greyed out if it’s not available for this particular animation.