2nd Munch’s suggestion of training first, bike second. Not only will it set you off on the right foot, it will give you an opportunity to sit on different bikes and see what you like. Can’t emphasize enough you need to learn how to ride solo before contemplating a passenger, and that takes time and many miles. Personally, taking the responsibility for another persons safety is not something I would do until I was sure I knew what I was doing, and adding all that mass at the back changes how the bike handles enormously. Seriously, I would forget about a passenger for the first year or so. Concentrate on yourself and get good at riding. It also gives you more choice on a suitable first bike.
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