i let my girl self feed around 10mths old iirc. at first she is just poking the food as she dosent know how to scoop up the rice. so i got to help her scoop and move her hands near to her mouth so that she can put the food into her mouth by herself and she seems very happy to be able to do that. i didnt especially teach her how to self feed. it all comes naturally through trial n error and looking at other people doing that. kids learn through all these. at about 1yr 3mths she can eat perfectly well all by herself without needing me to help her scoop up her food iirc. at first i let her use a normal toddler's spoon but eventually i bought her those types that are bend at the handle so that she can deliver the food successfully to her mouth easier. now she can use simply normal toddler's spoon/ fork for all her self feeding sessions. finally we can enjoy meals together (she eats hers n i eat mine) at the same time.
BTW, its still messy now as the food will still drop onto the floor, onto her clothes etc etc. so i bought those bib that has a compartment at the bottom to 'catch' the food that drops. this minimise the mess. good luck!