That is quite ambitious as a starting point. You have to look to the 19th century when daguerreotypy started out and not assume they didn’t know wha they were doing because it was the 19th century. Silver chloride on a silver plate won’t cut it. On eBay you could find some iodine (resublimed will do) for not much and that will give you something to work with. One of the first learning curves is knowing the difference between good polish (say on silver cutlery) and daguerrian polish that will garner enough of a reaction with iodine to form the appropriate amount of silver iodide for becquerel development. The exposures will be long and you may need more than one coin to get to the stage of getting images – lots of polishing. I do like the coin idea though, I have a silver quarter from 1936 that an old daguerreian friend told me I should use to galvanise a dag plate with. One day in remembrance of him.