Eating a plant-based diet doesn't necessarily have to mean "vegan", it can also be that you're just trying to eat more plant-based products and decreasing the intake of animal-based items
A plant-based diet can still meet all of your nutritional needs, but there are a few nutrients that you need to pay closer attention to, so you need to be mindful of them when meal planning.
Those nutrients include:
Protein: found in tofu, tempeh, beans, nuts, and seeds
Vitamin B-12: found in fortified plant-based milks (e.g. soy, almond, cashew, oat, rice, etc) and nutritional yeast
Iron: found in beans, broccoli, and fortified cereals
Calcium: found in calcium-set tofu, broccoli, and fortified plant-based milks
Zinc: found in beans, nuts, and seeds3
REFERENCES:
Rizzo, N. S., Jaceldo-Siegl, K., Sabate, J., & Fraser, G. E. (2013). Nutrient profiles of vegetarian and nonvegetarian dietary patterns. Journal of the Academy of Nutrition and Dietetics, 113(12), 1610–1619. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4081456/
Bouzari, A., Holstege, D., & Barrett, D. M. (2015). Vitamin retention in eight fruits and vegetables: a comparison of refrigerated and frozen storage. Journal of agricultural and food chemistry, 63(3), 957–962. Available at: https://pubmed.ncbi.nlm.nih.gov/25526594/