Excel tries to format cells according to what you type and also tries to match existing formating.
To stop it formatting what it thinks you want, use a specific format, not General.
Select the columns that will contain times. Select the Custom format and enter "hh:mm", click OK
Select the columns that will contain distances. Select the Number format and select the number of decimal places you want to show, click OK
Your formats should now stay put.
In the time columns the ":" is not required, you can use a space or "-" or whatever suits you.
You could enter
h" hour(s) and "mm" minutes"
The text to display is surrounded by double quotes
Enter 02:15 in the cell and it displays as
2 hour(s) and 15 minutes
A custom format [mm] will display the time in minutes only e.g. 1 hour 30 minutes is displayed as 90
Times can be subtracted from each other to give the difference for use in your calculations