in regards to what you are happy earning paul 250 to 300 a week will not be enough to keep a business afloat and give you a wage,not sure of your financial circumstances but the cost of a van,constant renewal and upgrade of tools,fuel costs,work wear insurance,tax national ins advertising to get started etc etc etc adds up in reality you will have to double that cost weekly imo at the least
Wouldn't be a bad idea to work with another tiler/squad of tilers for a year or two as that way when you make your mistakes then there will be somebody with you to keep you right. You'll also be building contacts, getting to know suppliers and be able to do homers of your own as and when you get confidence, while getting a steady wage and an education. Don't see any way you could get several days a week work with no contacts and no experience, the only way to do so is to be on the circuit for a while before going it alone.
I dont think 4 weeks training would make you a tiler it takes years there is no better training than to work with a pro you have got to start at the bottom, have been doing it for 42 years and I am still learning ,but hope it works out for you good luck.