As mentioned in the Getting Started section, Form Builder app is included by default in every Webiny installation.
This also includes the Page Builder page element, which enables you to easily embed forms in any of your pages.
You can do that simply by opening your page in the page builder, and selecting the form element from the elements menu on the left:
Once you place the element on your page, you will be presented with the settings dialog, which will enable you to select the form, and the exact revision you want to embed.
You can either select a specific form revision, or just set it to always use the latest one.
Please note that this only shows published revisions, which means you'll have to publish your form revision before embedding it into the page.
More information on publishing forms and revisions can be found here.