Affordable bike recommendations

I don’t really know much about bikes but I just ordered the hamex observer for my 9.5 month old baby. I just to ride around on a stump jumper towing my 55lb blue heeler in a bob trailer. He’s too old for bike adventures now but I want to take my little 20lb dog on easy bike camping trips with my baby. I also am hoping to transition baby to the shotgun pro seating once he turns 2 or I feel super confident he is ready. So I’m looking for a bike that meets these criteria

54cm (probably for my 5’9”)

Easy ride handle bars not drop bar (I just want to be comfortable)

Fit hamex observer baby seat

To transition to shotgun pro

Fit bob trailer (for dog towing)

Fit back rack for gear and bike camping equipment

Light weight

Mostly road with a fire trail maybe once a year

City riding

Touring in Japan

Thank you for any help in figuring out a good bike