It is recommended you start tummy time from birth and do it regularly; It is normal for babies to find tummy time difficult to begin with. Use a variety of.
If you're concerned that your CV goes too far back (or is making you look “too” experienced), limit yourself to 10-15 years and then list your full background.
At a minimum, before you take the GRE General Test, you should know what to expect from the test, including the administrative procedures, types of questions.