If you're just starting to put together your first sentences you need to get the verb TER down pretty well. It's fundamental. TER is super flexible and you can build lots of really useful sentences around it. Try these out for size:
Tenho um problema!
* You can skip the "EU" -- it's already clear that it's I HAVE since "tenho" is always just "I HAVE"
Tem um restaurante por aqui?
* Here "TEM" is used to say "IS THERE"
Você sabe se tem um banco nessa rua?
* The first part, "Você sabe se tem..." can be used a million ways.