Accounts & project help

Hello all.

Basically I am new around here, I have been creating sites for a while and have moved to Webflow for it’s ease of use. However, I am trying to get my head round the whole plans and pricing etc.
I have an idea and basically you add a site plan per individual site in order to add them features to that site which I have done. But you can also have an account plan so you can bull clients you make sites for.

Basically, I have just created a new play around project to test out some new code ideas and transitions but I am unable to embed custom HTML code, and it would not make sense to pay a minimum of $12 per month for this site just to embed code, especially if it’s not to a customer or for a client?

Am I getting this right? Anyone who can share there information or experiences on this will be massively appreciated.
Thanks, Adam.