Agree completely that starting small is the best way to try out indexing. If none of your unindexed cookbooks seems manageable, maybe you have an issue of a magazine with recipes that would give you a good feel for the task, and the satisfaction of making more recipes accessible to you and others.
Two-finger typing will only be a burden when writing EYB Notes, because most of the fields, including Ingredients, have you select from pull-down menus. It's an exacting process, especially at first, but empowering once you've done it successfully: you won't have to wait for someone else to make the recipes in your lesser-known cookbooks available. Applying the categories while indexing also helps you learn & understand them better, making your EYB searches more effective.
I printed out the Store-Cupboard Ingredients table and the Ingredient keyboard shortcuts to have close by during indexing sessions, but keeping them open in another tab is also an option. Keeping the Recipe Types chart open is essential, even for experienced indexers. Have fun and best wishes in your indexing efforts!