All web hosting companies are different, so asking how long it would take to get setup can be a difficult question to ask. However, most web hosting companies use their own administration panels (a bit like cPanel) in order to get your account active quickly, so your setup time usually isn’t long.
However, if you have asked for a specific server specification, or a non-managed dedicated server, then your setup times may be slightly longer. You might be faced with some additional setup fees in order to physically build your server if your requirements are specialist.