How do I delete the initial portion of my ride without data?

[Gerald]

You can use Ignore Part to exclude the data during that period; it’s as simple as highlighting the section that should be ignored.

Ignore power, HR and/or pace for parts of activities

You can now ignore power, heart rate and/or pace for parts of activities instead of having to ignore all the data. This just excludes those portions from the power, HR and pace curves fixing issues with poor data interfering with “best effort” achievements, pace records and so on. Remember that you can fix data instead of ignoring it (try “Fix Data” and “Edit Data” on the Actions menu). This is a better option if your bad data just has drop outs or you have some idea of what the numbers likely …

To crop it, you could use Fitfiletools.com > Section Remove