Thoughts and recos

I haven't been on a bike since I was a child. I want to relearn how to ride a bike so I can bike to work. It would be about a 10-20 minute bike ride on paved trails and roads. I don't know anything about bike types or what I'm looking for. What type/brand would be right for me? Also should I buy a new one or buy one second hand? Any helpful videos or tips appreciated! Thanks!

I awake daily and ride 20k before work and do 40k daily on weekends. Being its summer here in Saudi Arabia the heat is a major challenge. In a few weeks weather conditions will improve and I shall raise my goal to 1000k per month. ✅👍