Welcome to YorkieTalk.
Congratulations on your new addition to the family.
For eye boogers, I use cotton balls wet down with warm water or sterile saline. Then I use a tiny flea comb to remove any remaining softened crusties.
Potty training varies from pup to pup. Some are effortless, some are more challenging. Do your part to set your dog up for success by giving Cooper ample opportunity to potty in the correct place. Praise him profusely for each good potty, "Good boy! Way to go! Woohoo!," and give him a small treat (I always use a kibble). Don't scold for accidents. Calmly clean them up with an enzyme cleaner to remove the scent that may attract him to return to the site.
Enjoy your boy.