Congrats on your first AR!
Don't worry too much about the specific ammo - "range fodder" is just range-fodder, and inside of the 200 yard line, you're less going to notice any issues with the ammo's performance than with your shooting skills.
Functionally, all "range-fodder" will be "dirty," but the AR-15 is a very resilient platform: learn how/what to lubricate, and you can enjoy extended shooting -for THOUSANDS- of rounds, without even the need to wipe the bolt/BCG clean, much less the need to field-strip the gun for a more thorough cleaning ( witness the BCM "Filthy 14,"
https://bravocompanyusa.com/content/Filthy 14 bravo_swat_10.pdf - which had crested 65k rounds, as of this thread:
https://www.calguns.net/calgunforum/showthread.php?t=1440137 ).
That said, unique guns -I .e.
YOUR unique Saint Victor, the one with YOUR serial number: not your brother-in-law's Saint Victor, not your father's Saint Victor, not your shooting buddy's Saint Victor, not your favorite instructor's Saint Victor....you get the idea
- oftentimes have unique preferences for ammo. As the owner of that gun, you'll need to find out what your gun "likes" and "dislikes," be it in terms of the type of performance it puts out downrange (i.e. accuracy/precision), or even function.
For new owners of any one particular caliber, I advise them to avoid falling into the trap of wanting to save a few bucks by buying in-bulk, simply because they don't know what their gun will "like/dislike." Instead, at least for the moment, look to diversify your buy with different grain "weights" (actually lengths) of bullets and different brands/makes. Typically, for range-use, you'll be staying with the two most common: 55 gr. and 62 gr., and there are numerous choices to be had for these, in various makes and brands. Buy at-most a box or five (20 to 100 rounds) of each, so that you can experiment. Understand that most casual shooters' biases towards certain ammo is just that: biases based on their own experiences - your mileage can, and most likely will, vary.
One thing that is worth noting is that range-limitations on ammo are not uncommon. If you purchase ammo with a "steel core," such as the common M855 "Green Tip," be aware that some ranges - particularly indoor ranges or ranges featuring steel targets - may not allow you to use it.
Also, buy a few different types of magazines: Magpul P-Mags (either Gen M2 or Gen M3) are both cheap and plentiful and are among the most highly regarded full polymer-plastics available. If you like aluminum, Okay/Surefeed as well as D&H (OE makers of Brownells, BCM, and others) are similarly highly regarded. If you like hybrid -poly body with metal feed-lips- look to the Lancer L5AWM. For all-steel, Duramags. As with the ammo, UNIQUE guns will "like/dislike" certain magazines - be it from how easily the spent/empty magazine drops-free to potential issues with the fit of the magazine into the gun (i.e. certain makes/models of lower receivers don't play well with the Gen M3 P-Mag's over-insertion stop), so again, buy a couple, diversify, verify/vet - and only then invest.
Magazine problems are also one of the biggest causes of functional (and even accuracy) issues with the AR platform, which is why you should treat ALL of your magazines disposable goods: like tires or brakes for your car, you want the best you can afford, but you know as you put them on that they are going to wear from use, and that you'll have to replace them eventually. Since magazine issues can pair with ammo issues to cause a true multi-variable problem, this makes for yet another reason to think of them as disposable. As soon as you get a magazine, mark it in a not-easily removable and unique manner (many prefer their initials, paired with a number) so that you can "track" that magazine with-certainty. This will allow you to work through your troubleshooting matrix in a more logical manner.