Yes, you can use the free version of Canva!
Canva is well worth the investment and is by far the best graphic design tool. I have a link where you can get the FREE trial offer for the Canva Pro subscription under the getting started section.
If you intend on creating resources to sell, you must have a Pro account to adhere to Canvas copyright terms.
Also, if you are a teacher and you are using Canva strictly for personal use only you can sign up for the free Educators Pro account.