I start from the bottom and work my way to the top, about 1.0-1.5ml max on each site. Calves quads glutes triceps biceps delts then next week start over. The less of an amount you use the less the (chemical) inflammation is going to be. The more inflamed you make an area the more susceptible it will be to scar tissue. Scartissue is gross, aspirating oil from a previous injection, gross sight. And leaves for a less than optimal absorption!
Get used to it and start pinning new spots, use slin pins and low amounts on new areas such as biceps and triceps. 0.5ml is a good starting point. All muscles hurt in the beginning, worst is quads imo. But everybody goes through that phase it seems like. You can get a nice pump from injecting 1.5ml in both biceps and both triceps the day before arm day. Feels like they are going to explode!