WordPress hosting and plugins

Ok.

I have recently taken over a website that was through Wix that has a domain purchased through by namecheap.com. I wanted to use WordPress so I made the mistake of “mapping my domain” on wordpress.com. I have since switched to shared hosting using cpanel and softaculous and have since downloaded the wordpress app- I have done 2 websites through this process before. However, I still do not have the ability to use plugins!! I thought that by accessing my website through the softaculous would fix my problem.

my url although is being directed to the right site- is still mywebsitedot.net.wordpress.