my 1yo boy wouldn't let me brush his teeth and wouldn't take his medication..help!

Perhaps you can consider letting him brush by himself first then you follow up with another round. I explain to my toddler (then and now) that I just want to check and make sure she got every tooth cleaned so that she doesn't get any decay. We also read a picture book about tooth decay and explained the negatives about it so she could understand. As for medication, I always give my lo advance notice that we have to take the medication and I keep asking if she's ready to take them. maybe you can ask if he wants to read a book first then take the medicine? If you have those doctor toy set, I find those helpful in role playing and explaining to the lo why they need medication. I also found using a syringe versus spoon feeding the medication. (at least I don't have to worry about the spills.) This link below is pretty good reference. http://www.janetlansbury.com/2016/02/the-secret-to-helping-kids-take-medicine-without-a-spoonful-of-sugar/