The best O365 subscription to conduct testing on SharePoint Online

[Santosh2993]

Greetings, 

I am looking for a subscription of O365 that will allow me to conduct testing experiments on, instead of doing them on the active real SharePoint online. such as creating sites, subsites, lists, DLs, permission, etc.

I've checked the cheapest one, 5$ per user per month, Business Essential, but it is not clear what is the space size of SharePoint. is it part or sharing the space of OneDrive 1TB.

What are the minimum users that i need to subscribe for, so i can do testing successfully?

Also, can I use may original ID for business to sign up for the new testing subscription? or I need to use personal email address.

For the premium package, there is an offer "Special offer: 1 year free custom email domain.", does this means that the other packages don't have domain?

Thanks and Regards. 

Muhittin.

[#2 · Accepted solution]

Sign up for a dev tenant: https://docs.microsoft.com/en-us/office/developer-program/office-365-developer-program-get-started

[#3]

@Vasil Michev  thank you for the info, I have started my subsciption, but what will happend after 90 days, can we renew it?