You can train Fletching with the
/fletchcommand. For example,
10000. To start off training Fletching, you will want to
/chopsome logs for arrow shafts, and then
arrow shaftthem into arrow shafts. Alternatively, you can buy logs or unfinished fletching supplies from the #grand-exchange channel in the support server.
To see all the items you can fletch, check out the Fletching Wiki Page - most of the items found there are fletchable in the bot, having the exact same level and item requirements.