Wish you the best of luck.
I don't know off the top of my head any practice sites for beginning manual testing. But there are a few for other purposes I know of these,
Security - https://www.owasp.org/index.php/Cate...ebGoat_Project - Web Goat is a web server with security flaws purposely built into the system. Its mean for security testers to learn how to test for different types of security vulnerabilities. (I think perhaps reviewing the XSS and SQL injection would be good to do.)
Automated Testing - the-internet.herokuapp.com - the internet is a web server with a few purposely designed bugs for automation engineers to practice on.
Load Testing - SOASTA Store - Has several bugs in it that's revealed by load testing. Mostly around capacity and availability
I think you'll be in good shape as long as you have a good thought process and check list in your head to go by and be able to talk the interviewer through your thought process. In general, they'll probably only give you an hour of each interviewing employee's time.
Here's probably how I would talk them through things in an organized way.
* Functional requirements (ask lots of questions around this, clarify as much as you can up front)
- what is it required to do.
- what should it not do.
- what do the requirements imply, and how do these requirements affect other requirements. (ex: required field implies that there is an error displayed upon submission)
* Non Functional requirements
- Technical Expectations
* Expectations of the different pieces. (ex: a date field should only take dates, a text field should have character limits)
* Security considerations (for a web app you might think of the OWASP top 20)
* Capacity, Availability, Reliability (these 3 are hard to test manually, but just mention that given the resources you would test it)
- User Expectations
- Error checking
- Clear wording, spelling, grammar
- UI layout is clean and organized