- Is it Possible to use powerform free into the website without limitions?
- if there is limitations on free plan which plan I need to purchase to get the full access?
- is it possible to redirect user on the url of my website after successfull sign?
I tried to get the answer through reading their documentation but I was unable to get clear payment plan for powerforms.

PowerForms are useful when you don't want to write any code to integrate DocuSign into your website. They are a quick way to gather signatures if you don't know who is going to sign. They do have a bunch of limitations, one of them is that you can't really customize the experience for your users. PowerForms come with Business Pro Plan and above - see https://ecom.docusign.com/plans-and-pricing/esignature for more information about features and prices.
I would suggest you use Embedded Signing and maybe even look into the Focused View option that gives you more control, more smooth experience and the ability to either redirect after the user signs, or not even leave your site, so you just use a JavaScript event that calls your code to update the page however you like after the user signed.
https://developers.docusign.com/docs/esign-rest-api/how-to/request-signature-focused-view/
HTML: