When is the best time to run Facebook Ads?

Wait a month or two (because you need to have good enough performance from one platform before testing new networks because it’s always an investment to start a new network and therefore a new learning period) and then launch a Facebook remarketing campaign.

Should I run LinkedIn ads?

It is likely that LinkedIn campaigns to warm leads (aka remarketing) could be a good fit, but LinkedIn campaigns to cold leads is only a good fit for a few narrow industries.