Welcome to the HCM!
Bump on your neck seems to be a lymph
node.this is a very common finding as benign reactionary enlargement of lymph nodes occurs whenever there is focus of a infection in their drainage
Swelling in your armpit can also be a lymph node or inflammed cyst
Both these conditions are benign and can be easily treated.you can visit your physician and get examined.
hope this will help you!