Some issues have been coated with fluorescent material. Fluorescent tagging was introduced to enable the Post Office to use automatic cancelling equipment. An ultra-violet light is needed to detect this. To help you decide what to collect, here are some ideas for the kind of collection you might start. You can start several different kinds, if you want - as we said, its all up to you.
Many new collectors choose to collect modern stamps from their own country.
These stamps are readily available and are somewhat familiar. You could easily begin a collection of 3 countries, having ties to each. There may be family still living in France and the USA who will save their stamps and send them to you. Many new collectors have friends in other countries who also collect stamps. The Internet is a fast-growing means for people meeting and making friendships.