Like any other hobby. Slowly. Learn information online, tv shows, asking people who are good gardeners. Trial and error. Be observant during the trial and error, and then check what went wrong and how to do it better next time.

As for insects, you will encounter them. I wear gloves while gardening. I’ve been gardening a long time and never been bitten by a spider. So it might be a matter of small steps and maybe start with pot plants where there is a very low chance of insects and move up to outdoor gardening when you feel ready. Maybe reading up on the different kinds would help to feel better? Many insects are not only super beneficial to a successful garden, but absolutely essential. For example bees and worms. Good luck! Gardening is a fun and peaceful hobby. Oh and almost forgot, Gardening Australia on ABC is an excellent show with very good information and inspiration.