Slow WordPress? Is it normal?

I have noticed a recent website I developed is quite slow once it is online (on loading homepage). Does anybody have any advice to avoid a wordpress website being slow?

Here is what I am doing on this website:
using “WordPress pages” as my web pages, homepage is set as one particular page.
Other important note: the hosting company I am used to work with is using IIS, is it better to host with apache servers?

Thanks!