Transferring vhs and cassette will occur in real time, so whatever the length of content is, is how long it will take to record (not like digital files). A long tape you could just leave and go eat lunch, but a bunch of little clips will be annoying unfortunately.

If you're willing to spend money ($140) you can buy a little capture device with a screen, like this, that you just plug into and record to a USB drive, no computer needed. I've never used one, so read reviews! The same company also sells this cassette to usb thing if you dont't want to do the audio cable method described below.

Otherwise, You just need a capture card for your computer, Amazon sells lots of usb ones, some very cheap like this ($13) which might be a pain to setup and capture from if you aren't wanting to do some troubleshooting if it doesn't work, but Personally I would go with something like this Hauppage, or Roxio ($50) they are trusted names and comes with capture software. Otherwise you'd need something like adobe premiere or another video editing program that can "ingest" from the usb device.

You could probably record the audio cassette tapes using that video capture card, though I'm not 100% it does an audio only capture. Otherwise you can get a 3.5 stereo cable and go from the headphone out of your player/walkman into the audio input (usually a pink mic input or labeled w/ a circle with arrow pointing up) on your computer. If your cassette device is rca (red/white) you'll need an rca to 3.5 cable. If your computer is a laptop or doesn't have an audio input, something like this should work. Then use a software like Audacity to record.