I'm glad everyone else gave you a good talking to because geez I'm glad you came and asked questions here before buying some fuckin Tren and blasting off

Im still just a bit confused as to where/why to inject in certain spots, why to never inject in the same spot, and would like to just solidify my knowledge on injecting.

-It’s possible to inject in the same spot more than once. The main rule is to avoid the development of fibrous tissue at the injection site. This depends on factors like injection frequency, the quality of the oil carrier, your individual sensitivity, and other reasons.

the Tren oil I am looking at has reviews saying a Insulin needle flowed just fine with it, so I will probably go with those.

-Good thinking, but it’s too early for you.

Also, I asked the vendor a question on their products, but they said they could not "offer guidance". 

-This isn’t personal neglect towards you. The source has too many urgent matters to spend time on lengthy online consultations for beginners. Just take it into account.

I was going to order their Tren 100, but noticed they also
offered a Tren / Test combo in one. I was hoping to learn from them if there was a benefit to offering both in one shot. 

-There are no benefits

then I searched this site, I was led down a road of what seems to be a constant debate of taking those in combination, how Tren is x5 more powerful, so Test would not bind to any receptors since Tren was so much more powerful, but if you go xx weeks, new receptors could accept Test..

-Don’t bring up such topics for at least a year or two.

My main question was just, in taking a combo shot such as Tren/Test, does that lower the side effects of Tren on the body

-No.

and also act as a PCT replacement?

-No.

Or is a combo shot such as that simply to offer Tren, but also Test for people with low Test?

-No. There are several reasons:

*Testosterone is the classic foundation for any cycle. For most bulking cycles, dosages and durations for Testosterone are determined first, and then additional compounds like Tren are added if needed.
*Tren significantly suppresses libido and worsens erectile function. For this reason, Tren is often combined with Testosterone, which helps partially mitigate these effects.

Bro avoid tren... it is very dangerous and unhealthy

The reason you do test with tren is because the tren does not aromatase, so you need the test for that or your estrogen will plummet. Some prefer higher test some like it lower than the tren dose. The test is not too do anything with the tren side beside the estrogen which really isn't a side by technically u could consider it one. The thing best to use with tren to make it as smooth a run as possible is masteron. Which is why if you've been looking into blends you'll see so many test tren mast mixes. The reason for mixes is to inject less oil. Also. Only thing is they're set doses so you can't play with it. You can get separate vials of each compound in the blend and add what you want to change ratios, for all that though you might as well just get em like that in the first place. Though you would still be cutting down on infection volume, and maybe save a couple dollars.
But listen to anvil. He's right.
I was just answering your questions you were asking about the compounds for info. Is not advice.

How long have you been in the gym? What’s your body fat % looking like? Is your diet on point? Is your rest on point?

There’s lots of things to consider before you take the plunge and having the above things in order will only benefit you in the long run.

Running gear on a crappy diet and crappy training will only net you crappy results.

Depending on where you’ve been reading, it’s recommended you get down to 10-15% BF as, from what I’ve read, the fatter you are, the more you’ll aromatize while on cycle. This will require more estrogen lowering/blocking compounds than if you just started out leaner.

Just my $.02 as a newby as well.

For your first cycle test alone should give you amazing results.