How to record if and when my Macbook is opened
Try the command last

It will show you every login since the last reboot.

Open Terminal and just type (using my dev xserve as an example)

[admin@xserve1 ~]$ last
admin      pts/0    allans-imac.home       Wed Mar  2 23:20   still logged in

utx.log begins Wed Mar  2 23:20:07 EST 2016
[admin@xserve1 ~]$ 


This would be correct since nobody but me (the admin) had logged into it.