From "pure" PHP to CodeIgniter

Greetings all!

I am very new member on this forum so let me introduce myself a bit. I am self-thought freelance PHP developer since 2015. I develop alone, so I consider myself more or less capable in PHP, javascript, jQuery, CSS, html, SQL (MySQL). So far, I had some 20-ish project, some with several 10s of thousands lines of code. I am quite aware that some of my development practices are not the best so I am trying to improve myself, more so as I started one large project. Anyway, mostly for security reasons, I decided to use a PHP framework, and after reading internet for several days, I picked the framework - CodeIgniter.

Any general thoughts, suggestions, comments? Is this the right choice?

Cheers!