Well the sentences are pretty good. However just the first sentence "If I'm late, go home by your own" need some correction. You could either say "If I'm late, go home by yourself" (OR) "If I'm late, go home on your own"
Also here are few examples of "If I'm late.." as you requested -
1. "If I'm late, make sure to lock the doors before you go to sleep"
2. "If I'm late, please make dinner for yourself"
3. "If I'm late, please wait near the bus stop for me"
I hope these help. You can always reachout to me for any further help. 😄