Normally I suggest the 8 hour package. This will cover the main areas that need work, so that you can get maximum benefit early on. After the 8 hours, you might be confident enough to use your knowledge and materials to improve on your own. Or some people want to continue and buy more packages - it's your choice.
However, there is no set number of sessions – it depends on your goals, your budget and how much you practice outside the sessions.
If you have a very limited specific need (e.g. difficulty pronouncing just one or two sounds, or an interview practice) then it may take only one or two sessions to achieve what you want.
The choice is yours – most of my clients have one hour per week. Some people take more frequent sessions for the first few weeks, then have occasional top-up sessions.
Yes. This is essential. I will give you exercises to practice at home – most of the work will be done by you between sessions. You need many hours of practice to change the habits that have formed over many years. Like any other complex physical skill, your new habits will only become automatic after many hours of regular repetition.
It depends on your individual needs, but these may include:
This depends on many factors: your goals (do you just want to speak a little more clearly? or do you want to sound as close as possible to Standard English?), your motivation and how much you practice. Some aspects of pronunciation can be quite easy to change, others need a lot of hard work, while others may be virtually impossible to change completely. Sometimes progress can be very obvious, at other times you will feel you are making no progress at all. This is completely normal, and it varies a lot between individuals. However, with regular practice between sessions you should notice some useful improvement after about 8 sessions. Significant long-term changes may need several months of practice.
If you are an adult, then even after many years of work on your accent you will probably always sound a little non-English to a native English speaker. Realistically, you can aim to improve your accent so that it has minimal effect on your ability to communicate.