I need the opinions of graphic designer friends.

[HaveAGoodLuck]

Hello, I am using intermediate level Photoshop and Illustrator and I have learned how to use them, thanks to God. I sell phone accessories in e-commerce. I will soon be launching printed products. I am searching for websites where I can find vectors, psds, and illustrations that I can print. I am looking for both paid and free sites. I will be getting a membership, but I do not know which sites are good. If anyone who has knowledge can recommend sites where I can find such drawings, I will sign up for a membership. I would sincerely appreciate it if those who respond in advance. Thank you for your interest. The products I print are MUG, CUP, PEN HOLDER, ASHTRAY, COASTER, T-SHIRT, PILLOW.