As a junior dev you shouldn't be able to screw up big time, if you do, that's on the team/company, not on you. As a senior it is trickier, but usually no one should be able to screw up monumentally, if they do it's a lack of internal process, not on the individual (exceptions being malicious intents).
Changing internal processes without being a decision maker inside the company (e.g. an influencial manager/lead, the owner, a vp, etc.) is hard, even if there are clear benefits. If there of things that make no sense, there are no horizons for the improvements to come and you are not learning from your seniors, consider if it makes sense to move forward. Trying to change internal processes at reluctant employers is a common cause of immense frustration (and burnout), don't let yourself get caught into that.
Changing internal processes without being a decision maker inside the company (e.g. an influencial manager/lead, the owner, a vp, etc.) is hard, even if there are clear benefits. If there of things that make no sense, there are no horizons for the improvements to come and you are not learning from your seniors, consider if it makes sense to move forward. Trying to change internal processes at reluctant employers is a common cause of immense frustration (and burnout), don't let yourself get caught into that.