If you're explaining the main points, at the beginning of your presentation, you could use the following expressions:
"First of all, I'll be talking about [this, that and the other]."
"Then I'll be going on to discuss [XYZ]."
"In conclusion, I'll be presenting some possible solutions to the problem."
Of course, there are other ways to say the same thing – perhaps other members will have better ideas!
All the best,
Student or Learner