To try Dolibarr ERP & CRM now, you have 2 solutions :
A free dedicated instance, only for your company: Create in 2 clicks a dedicated clean and secured instance, and start to use it as if it was for a production usage. Instance and data are yours and dedicated to you.
Test on the shared instance: Test immediately using the world shared instance of Dolibarr. This instance is not dedicated to you, but used by everyone, and is updated/reinitialized several times a month with last development version (so may not be stable).