Help Weaning and teething

Hi my lo is 17 weeks and has her bottom 2 teeth through ( i know very early) anyway hv has suggested weaning her as she shows all classic signs even though these are similar to teething

SO going to start today but i feel really nervous not sure why but i am going to give her some baby rice at lunchtime feed (11.30) any advice how to try and calm down and how many days before i try her with some puree fruit or veg

aaahhh its all confusing