With drug testing, even with drugs that are known as safe to use in humans, it will take time to collate results. So WHO (or whoever) can say "these are drugs we are potentially testing", but it will still take weeks to generate data that will show whether an individual drug does cause better outcomes.
For example, if a drug delayed the onset of symptoms for a week, but then the symptoms you got were worse, you wouldn't want to take this drug. Again, if a drug delayed the onset of symptoms, but didn't actually improve outcomes long term, you might not want to use this drugs.
I do think there are some promising signs that antivirals will help us fight this, but generating the data to help us decide which ones will be most effective is still a process that will take weeks, if not months.
I'm not sure it would be helpful to put orders in for any drugs at this stage- but hopefully by the end of April there will be more useful data out there, and doctors will be able to use drugs to help patients as well.
It's also hard for countries with overwhelmed medical systems to produce much meaningful data, so a lot of this data needs to come from countries with less people in hospital, again, this will take time.