Retainer agreement to collaborate with me on web app development

I'm looking to retain a person on a monthly basis to collaborate with me on a web app build with python and mysql back end and javascript front end. Ultimately I'd like to build it all myself (or be able to rebuild it all myself) but I need someone to tutor me on bits and pieces as we go along. I might need something in the region of 5 hours a week including video calls and email time and time for you to go away and figure something out before coming back to me.

The project is currently on my laptop server. If you're interested we can discuss the best deployment option for collaboration and the initial monthly fee. Some months will be more work some months less. I expect to be going for an initial 6 months to begin with.

Budget around £200 per month.

Thanks,

Rob