The strict pull-up is a bodybuilding-style pull-up in which the purpose is to maximally contract the muscles of the back and arms – mostly the lats, biceps, and forearms. The rest of the body is meant to remain in enough tension to maintain a rigid structure. With the strict pull-up, the body should not move except for those joints which are required to perform the movement itself, the elbows and shoulders. All other joints should remain relatively stationary, as they shouldn’t contribute to the force production required to execute the exercise. This is the classic exercise that people think of when they hear about pull-ups. (LINK)

So, basically you need to increase muscle hypertrophy — in particular, the lat and bicep muscle. You have to train your core too because you have to keep your other parts of the body tense while doing pull-up, so it is easier for you.

Below will be the exercises I can think of to improve your strength. If you do it properly, you should be sore the next day. Please do not do the same workout consecutively for two days because when muscles are sore/ torn, they need at least 24-48 hours to repair (usually 24 hours, unless you really trained hard). Switch the muscle group you trained daily, e.g., Monday train back muscles and arms, Tuesday train shoulders and etc. But actually I can’t think of any other part of the muscle that you need to train, so I will just give you what you can do to improve the strength of your back and arms. So as long as you rest on the next day, it is fine.

Do some sprinting intervals to improve your general fitness. E.g., 30 sec sprint followed by 30 sec rest, repeat for 15-20 minutes. If it is too tough, do 20 sec sprint and 1 min rest.

Back & arms
Warm up with 5 mins of jogging. Then warm up your lats with lighter weights first. Always remember that form over weights. I’d rather you train with a proper form than a compromised one due to too-heavy weights. Because you have never lift weights before, so I really don’t want you to get injured. You can ask Jacob since he gym.

Lats pull-down 3-4 sets of 12 reps (wide grip)
DB row 3-4 sets of 12 reps (alternate your arms if you do not need to rest, saves time)
Reverse grip pull down 3-4 sets of 12 (slightly narrower grip)
DB skull crusher (check Youtube if you do not know how to do) 3 sets of 12
DB tricep kickback 3 sets of 12
Tricep dips 3 sets of max effort (at least 25 reps)
DB bicep curl 3 sets of 12 (do not choose too heavy, watch your form, if you feel it mostly on your forearms, you probably should drop to a lighter weight)
Push up 3 sets of max effort (do it properly)

Do this routine at least 2 times a week. rest for 60-90 sec between each set. Bring a watch or use the clock in the gym. Slowly increase the weight if you feel stronger.

Core (do this 3-4 times a week)
Plank 1 min – rest 30 sec
Side plank 1 min – rest 30 sec (for both side) * Do this for 2 rounds. Slowly increase to 3 rounds if you can.
Hollow hold 30 sec followed by 30 sec rest, 5 rounds.
Youtube has a lot of great core workout. Take a look at this one – LINK.

Recon ron Pull-up Programme
When you can do at least 6 proper pull up, start with this programme. The review of it is not bad. The website doesn't list the directions or specifically what you need to do however. At the top you'll notice it says WEEK 1, 2, 3, 4, etc. During each week you will perform 5 sets of the number of reps listed in the column, for example in week 1 you will do 6 reps on the first set, 5 on the second set, etc. You do this Monday through Saturday and on Sunday you take the day off and do nothing to allow yourself to recover from the previous week. Then you'll move on to week 2, however in MY (online author) personal experience I found that it moved a little too quickly, so I spent 2 weeks on week 1 before moving to week 2 where I spent another 2 weeks before moving on to week 3. If you're stuck on a certain week and you've been stuck there for more than 2 weeks without being able to improve to what's required on the next step, then take 5 days off and don't do a single pull-up.

Pre-recon ron pull-up programme
You can do this concurrently with the strength training workouts. Ask me if you have any questions.