For beginners I recommend using either the plastic seedling trays or recycled containers and inexpensive plastic or Styrofoam cups.
There are so many options for materials and many sizes of containers, it can be overwhelming: plastic seed trays and cell packs, various biodegradable containers that can be planted with your seedlings, recycled or DIY containers, and soil blockers. For beginners I recommend using either the plastic seedling trays or recycled containers and inexpensive plastic or Styrofoam cups. These are reusable year after year and save you the time required to make your own pots when you are already taking the time to learn to garden.