That's good that you are fit and get plenty of health checkups. I would have that cramping calf looked at, though.
I say it doesn't do harm to err on the side of caution and take it slow in progression, you're not going for a competition.
At 3x6-8, if you have one workout you raise weight each week, if you have two workouts you raise it every two weeks. So over 12 weeks of alternating workouts you'd add weight 6 times.
As a fit 26 year old male without injuries, you should be able to start at,
deadlift, 60kg
squat, 40kg
bench/row, 30kg
overhead press, 20kg
On squat and deadlift, add 10kg (a 5kg plate each side) until you pass your own bodyweight (eg if you are 72kg, you'd hit 80kg, if 97kg you'd hit 100kg), then add 5kg (ie a 2.5kg plate each side).
Bench and rows, add 2.5kg.
Overhead press, add 2.5kg, but soon you'll be looking for smaller plates.
At some point you may stall. For example, you may be aiming at squats 90kg 3x8 and achieve 8,8,6. This is where you remember it's progressive resistance training. You progress by more, more and more - more weight, or more reps, or more sets. Well, 90kg 8,8,6 is more than 90kg 7,7,7 was, so well done, you progressed.
Next time you come to the gym you manage 90kg 8,8,7. Again you did more, well done, you progressed. But the third time you only get 8,8,7 again. You didn't do more weight or more reps, so you have to do more sets. Do a fourth set, even if you only get 3. Thus 8,8,7,3.
Next time you will almost certainly make 8,8,8. So then next time you can go for 95kg 3x6. And that is how you deal with stalls.
I still say 3 exercises a session is enough to begin with. It's better to go balls-to-the-wall in 3 than have to hold back some energy to complete the extra 2. This won't make much difference when you start, but later on when you're shifting significant weight, you'll feel it. I know because I did 5 exercises a workout (squats, bench, rows, OHP, deadlifts) for two months, very hard. 3 exercises a workout is more sustainable over time.
Drink plenty of fluids during your workouts, northern heat and humidity can kill you. Even down here in Melbourne I have people I train knock back 500ml of water before their first rep, 500ml at the end - they drink according to their own thirst in between, usually another 500ml. They've done studies, most people drink about half what they're actually losing in sweat. So you have to drink more than you want to.