Start every sentence (and the first word of a quotation) with a capital letter and end it with the correct punctuation mark.
Please note this extract from the Posting Guidelines:
Thread titles should include all or part of the word/phrase being discussed. (Avoid phrases like "HELP!", "Urgent!", "translation please", "how do I say this", "I'm new" and similar expressions.)
'They are/this is my dad and my mom' would have been good for this thread.
When you introduce someone they are near, so "this" is the right word. If you were pointing out your parents from across the room, you might say "That couple over there, they are my parents."
American English might be different, but the standard order in British English is "my mum and dad" (also note the spelling of "mum" although some regional usage includes "mom").
There is also no reason to repeat "my".
This is my mum and dad.
Note that we don't say "These are my mum and dad" even though we're introducing two people.