[novas0x2a]

What sort of timescale do you mean by "soon"? When you start doing a new exercise regime, it's really common to experience DOMS[1] for the first few weeks. It really feels like the end of the world (personal experience) but it's not actually an indication of real injury and it's generally safe to push through it if you can (and doing so can actually alleviate the pain, at least temporarily). Distinguishing between DOMS (where it's safe to push through) and real injury (where you definitely should not) comes with a bit of practice, and honestly, compared with the few times I've hurt myself for real... DOMS felt worse. Except when I slipped while holding weight and broke my toe. Strongly recommend against that :)

If you're experiencing exercise-induced injuries immediately during a workout (and if you have a budget for this), it might be good to talk to someone about what you're trying to do. Some gym plans include a bit of consultation time with a staff trainer, and they can probably help you work around whatever the problem is, sometimes simple adjustments can help (particularly anything involving preexisting shoulder damage, most of the commonly-recommended shoulder exercises have substitutes that are less risky for already-damaged shoulders).

1. https://en.wikipedia.org/wiki/Delayed_onset_muscle_soreness