If you would like to do the home blessing and chalking of the doors yourself, you'll need the Epiphany Blessing prayer sheet and blessed chalk. Churches will often put blessed chalk out on Epiphany Sunday but you can also bring chalk with you and ask the priest to bless it after Mass.
The traditional date of Epiphany is January 6. Liturgically, we will celebrate Epiphany on Sunday, January 8 this year. Any day in the weeks around Epiphany will work.
It's also nice to bless the rooms of the house with holy water, so be sure to grab a bottle from church if you don't have some at home.
To learn more about this tradition, check out:
Epiphany Blessing: Chalk It Up to the Wise Men
Epiphany House Blessing with Chalk, Catholic Icing
How to Bless Your Home with Epiphany Chalk