I am a beginner looking to start investing for the long term. What are some low-cost options for index funds and automated portfolio management that keep fees minimal?

We ask the same underlying question in different ways.

• I am a beginner looking to start investing for the long term. What are some low-cost options for index funds and automated portfolio management that keep fees minimal?
• What are the best low-cost platforms for long-term index investing, and is it worth moving my assets over from a legacy brokerage?
• I want to start investing for the long haul but need to keep costs down. Which automated investment tools or index funds are suitable for someone just starting out?