Can I take. Dayquil. While im taking lorazepam. 5 mg?

Probably. But, it would be a good idea to be careful about driving, working with dangerous equipment, knives, etc.
Probably safe. Dayquil does have psychoactive medications in it. It does not however, have sedating medications in it which would be the concern when mixing Lorazepam with another substance i.e. Alcohol.