I'm not being condescending at all in this post even though it's going to sound like it. I'm just offering advice like the other guys.
I'm 29 years old now. At age 16 I started my apprenticeship in Tiling. Piece of cake, in a few weeks I'll be knocking out bathrooms like a pro!
Honestly my friend I couldn't have been more wrong. You see there's so much more to Tiling than sticking tiles on the wall. Just look through this forum! I left my apprenticeship at age 19 after 3 years and I still felt in comparison to the blokes I worked with like I wasn't a time served tiler. They had knowledge and skills that are truely hard to put into words. Every job is different. We would spend hours setting out tricky floors and prepping jobs etc. There's so much I learned from them and I was good but no were near good enough to go out on my own. It takes years of dealing with misshapen walls, hundreds of different tiles, different substrates prepared differently by other tradesmen, good materials / bad materials, tools, walls running unparalleled to each other, spotting mistakes made by plumbers / joiners / plasterers / builders that will effect the outcome of the job YOU'RE finishing for a paying customer. The challenges are everyday. It's more than just a skill in my opinion. It's more like a mindset that can only be developed by learning from experience over the course of years. As a novice you'll make mistakes as most apprentices do even time served experienced tilers make mistakes. It's part of learning but if you're charging customers enough to earn a living for yourself and want to be seen as a pro to make a business like Tiling work you have to learn from a pro. There's just no way around it in my opinion.
Again I'm not being negative. I just wanted to give you advice as I myself am currently working alongside a pro in my spare time to get myself more experience to maybe make the leap and go at it alone when I'm ready. I have always done jobs over the years in my spare time for friends and family etc + 3 year apprenticeship and I need experience. It can be done with time and dedication. I hope you take this advice and seek a pro to learn from even if it's for free.
Good luck mate