Preparing for a CS PhD in Undergraduate
The following constitutes my $0.02 with regards to your inquiries. First of all, some fragments of your statement caught my attention. I list them below:

"Eventually, I decided that I want to go into academia. Based on what I’ve read on the internet" - I would suggest you try and get some input aside from information you've gathered from the internet. Your current CS professors might be a good choice. Ask them about what PhD programs, about their experiences, about their opinions, etc.

"[...]but my undergraduate college will not help me on applications." - This fragment leads me to believe you attend a college (undergrad-based) and not a Research-1 university. Is this the case?

To answer one of your questions (the last one), see if (Summer next year) you could join a Research Experience for Undergraduates (REU) program. Those are usually big resumé boosters when it comes to Ph.D. program applications.