Well, as much as I like FreePascal / Lazarus, from what I found, there isn't much out there past the 'basics' while C has a ton of stuff for it.
It is a fact that there are many more libraries written for one thing or another in C than in Pascal. That said, there are plenty of well implemented libraries for "basic" stuff, such as math, trees, sorts, etc, in Pascal.
The C math library is likely fully implemented in Free Pascal and, if there is something missing, no doubt an implementation of whatever is missing is somewhere not hard to find.
and while he would just be starting to learn programming, I'm still learning Pascal myself. So I also would like to use some of the C stuff that's out there, but I don't want to have to mess with really learning C itself. Just cause.
Someone who wants to learn programming has a decision to make. The influence of the C language in programming is difficult to overstate. The most popular operating systems and other sophisticated software systems are written in C, the consequence of that is, anyone who is serious about programming has no choice but to become, at least, reasonably familiar with the C language and, that is really a bare minimum.
Maybe I'm lazy, but I think trying to convert stuff from C to FreePascal by hand would be a massive pain, cause I'd have to look up each function to see the Pascal version or write one if there isn't one and I'd be in trouble then if its not a simple one.
But IF I could just add like a converted C_Math (or whatever is needed) to 'uses' then go on with converting whatever I'm looking at from C to FreePascal, I think it'd be a lot easyer to do and help with learning.
But that's me.
Aside from the fact that a "magic bullet" that can translate any C program into Pascal does not exist, automated translations are, very often a bad idea. Manually porting C code to Pascal may be pain but, the success of porting the code almost always depends on understanding the original C code. Tools that automate the process may not, and often do not, result in a working program. Without any understanding of the original code, fixing whatever the problem is in the resulting translation will not be easy.
The real decision is, how much programming do the two of you want to learn ?. If the answer is "enough to write some capable programs" then, you'll do fine with knowing only Pascal. If the answer is "some really sophisticated programs", you can also do it in Pascal but, you'll need to know C because many applicable examples/samples will likely only be available in that language.
Pascal is a good choice because the language and the compiler encourage designing good code (note: encouraging is not the same as guaranteeing.) That cannot be said about C, on the contrary, if you want to write binary garbage in Paris that will stink in Tokyo, C is the language of choice (note: it is possible to write good code in C, just like it is possible to see a unicorn, it's all about alignment.)