Premier Rush Video Generally Slow

I am new to Premier Rush. I am finding delays in working in the program – especially watching video, which freezes for short blips often.

About my computer:

• RAM: 16 GB
• Processor Intel  Core i7-7Y75CPU @ 1.30 GHz 1.6 GHz
• Windows 10 Pro
• Windows version 2004
• X64-based PC

The videos are MP4 files, filmed from a live Zoom webinar we ran. Sizes of the original videos, which I am trimming down for use, range from 124,000 to 493,000 KB.

Related items:

• I am wondering if this delay is because the files are kept in the cloud. Is there a way to easily change where they’re saved to the hard drive, ideally moving them back to the cloud when I log off for the day,  so that they are still backed up?
• I will be getting a new computer later this year. Are there any parameters I should be aware of to ensure this works well in the future? The basic requirements on the web (64 bit, Windows 10) are already covered by my current computer, but if ideally I should have more.