That really depends on what you actually want to do .I assume that you are not brand affiliated so I think will be quite difficult . It would be worth giving some of the insurance companies a call to see what their requirements are in order to Accredit your courses . You would also need to get the permission of the brand that you wish to teach with as many would not give that permission out unless you are connected with them
If you are wanting to teach in FE you would firstly need a level 3 nail qual
Assessor and teaching qual PTTLS is a good start but ultimately DTTLS
There is a shortage of good nail tutors but be warned they are making massive cuts in the FE sector due to lack of government funding and it is a extremely stressful career as you will also need GCSE in English and maths or equivalent and you will need to embed English maths and British values in all your lessons to meet ofsted requirement
Think long and hard before investing your time and money !!!