In my opinion, the best advice that I can give you is this:
At first it's best to do only one or two sets of light-weight work, whether reps are on the medium or high side* (& it doesn't hurt to err on the side of caution). One way is to break in slowly with light weights low reps the 1st day you do an exercise, because the 1st time an exercise is done you'll probably feel like you can do a bunch -- & you can... but a day or three later you might not be able to move very well as a result (the body's reaction to new &/or strenuous exercise is often like drinking Long Island Ice Teas -- you can down quite a bit & think all's fine & well, but it eventually hits you big-time).
If you take it easy & increase either sets, reps, or weight slowly, then you'll most-likely get sore but not terribly so, and you'll most-likely continue training & do well (as opposed to getting so sore that you start missing workouts or get so low on energy that you tax your immune system & catch colds easily). Get the feel for each exercise 1st before increasing weight & before any quantum-leap in reps.
At the start, basic exercises are often good -- but finding out how to do them properly is very important (else you risk injury either immediately &/or down the road). In books you'll often read about doing an exercise with a "full range of motion;" often the proper range is a bit shorter than what the average layman thinks (so do your homework & as a general rule if anything seems uncomfortable, especially at or near the beginning or at or near the end of a rep, then chances are you shouldn't go that far anymore &/or you need to change the angle of your grip -- so stick the the ranges & grips that feel good to you... & since not everyone is built the same way, don't break this general rule just because your friend can do it a certain way without any trouble). Finally, check your ego so it doesn't get you into needless trouble (like trying to handle too much... you'll eventually gain strength in your muscles & tendons, & bones as well, but not necessarily equal strength in all areas simultaneously -- some tissues take longer to strengthen than others, so slow gains are safer than super-fast gains; & a needless injury can ruin your goal's time-table & sometimes even the rest of your life).
Some good basic upper-body exercises (as a start) are:
Delts: Military-Press (or one of its variations), Upright-Row, Bent-Over Lateral-Raise (or Reverse Pec-Dec, aka Reverse-Flye)
Arms: (Biceps) Basic Upright-Curl; (Triceps) French-Press (aka Upright Overhead Triceps-Extension)
Torso: (Chest) Push-Up (or Bench-Press), & Pec-Dec (aka Flye); (Back) Bent-Over Row (or Machine-Row), Lat Pull-Down to Front (or Pull-Up), & Top-End Dead-Lift (or any Hyperextension variation)
Abs: Padded Sit-Up or a standard Crunch; Bent-Leg (or Alternate Straight-Leg) Leg-Raise; 1-Arm-Weighted Side-Bend; & Pole (behind neck & across shoulders) Upright (or Seated) Twist [with abs, pick only one exercise each workout or even each week for the first 2-to-4 weeks so you'll know how each feels & then you can start doing multiple ab exercises... think of starting with little & then slowly building up from there: 1 set of 12-to-20 reps is a good start point)
Most beginners & many advanced trainers don't directly train Traps, Neck, & Forearms (as they are often worked without focusing on them when doing many different exercises targeting other body parts)... but even if you wish to do direct exercises for these muscles, the above exercises are plenty (& perhaps even more than enough) for a beginner... you'll need to conserve your energy, especially at 1st (at least until you make training an enjoyable habit -- else it might become a dreaded chore)
Generally, for Upper-Body:
* Low Reps: approx. 1-5
* Medium Reps: approx. 6-10 or 8-12 are common
* High Reps: approx. 12-16
Train the area that you feel needs the most attention 1st in a workout & the area that needs the least attention can be saved for last; next, should you split your routines, it's often good to train antagonists together (don't just think of grouping antagonist muscle-groups like chest & back, but consider grouping antagonist motions like Lat Pull-Down to Front & Military-Press).
There are other possible/good considerations, but this is enough for now (else it could seem overwhelming). Good luck with your plan.