The upright bike is obviously the most similar to a normal bike, due to the positioning of the body.
You would probably find it a bit different to the normal bike, because you're not cycling in conact with the surface below, which you will discover the first 2-3 times you use one, but the recumbent might offer more support for you, because it has a seat not a saddle, so you might find it a more comfortable experience, but you'd need to use both types to compare, however you can obviously alter the resistence on a recumbent bike as well as an upright, so that will have some effect on the way it feels.
Just try what you feel is best and take it from there and then just the experience(s), for yourself

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