When growing plants in containers there are some things to keep in mind for the best chance of success.
Choose a container 2”larger than the pot the plant is already in.
Choose a pot that can handle temperature changes. If the pot will stay outside year round choose a material that can handle these changes. Fiberglass, resin, concrete, and heavy duty plastic will last longer than unsealed terra cotta.
Provide drainage. If the container does not have drainage drill holes in the bottom so water does not sit in the bottom of the pot. A unsealed terra cotta pot will allow water to evaporate through the sides of the pot. This may be desirable when planting cactus and succulents especially if there is a chance of overwatering. This may not be the best thing for hotter weather and non drought tolerant plants.

Use potting soil –not garden soil. Potting soil will drain better and not contain weed seeds. Some brands I like are Dr. Earth, Black Gold, and Patio Plus.
Rocks or gravel are not necessary for drainage and may actually prevent water from draining. The only time I would recommend something in the bottom of the pot is if there is a chance the pot could fall over or blow over or if it is a huge pot that would require a large amount of potting soil. To weight the pot down put a few bricks or large rocks in the bottom where they will not block drainage holes. Placing smashed pop cans or upside down pots will take up space in the pot so less soil will be required in huge pots. If you are concerned about a little soil coming out of the bottom of the pot place a coffee filter or piece of landscaping fabric in the bottom of the container.
Place the pot in an area appropriate for the needs of the plant or plants. Sunny, shady, morning sun only? Check plant labels, research for your climate, or ask a me.
Check whether to water by sticking your finger into the soil up to your first or second knuckle. For most plants the soil should just be beginning to get dry before you water again. When watering throughly – not just a quarter cup.