There are numerous potential sources for genealogy research within the family. Even old envelopes and receipts may provide addresses or useful information about lifestyle. Old passports, diaries, postcards, and letters. church records, photographs, newspaper cuttings give more help. It is amazing what people keep. poems, short pieces of prose or travel memoirs would be great finds. You might find sketch books, drawings or paintings. You first need factual information to complete your family tree. This means birth marriage & death certificates, divorce settlements. Later look for other materials that will help you place your ancestors within a context. Other relatives at the same address, professions and age can be given by census returns. Other source materials include medical certificates and medical records, baptism or christening records, wills, property deeds, account books, notebooks, family portraits, identity cards, exam certificates, medals & trophies, invitations, greeting cards, journals. Other family members can help and there are many online resources using the internet. Some the most useful resources are provided by the mormons who believe in baptism after the age of 8 years, either in life or in death so that even previous generations can be given the retrospective opportunity to choose their faith. You will need to find out where county archives & parish registers are kept. Hopefully you will find out something about your heritage, your ancestors & have an interesting hobby.
Eventually, you will find yourself in old Graveyards & Churchyards looking at Gravestones because they are the oldest records.