I don't want to discourage you but using 5w50 oil grade on a 43k kms Altis 1.6 is not a good choice, to be honest, I have already been fool enough to listen to the Toyota dealership mechanics who are just eager to sell their crap labeled as Engine oil, I suggest you stick with the 5w30 oil grade.
Secondly, changing brake disc, coolant, transmission oil, and brake oil is not necessary at this mileage, please consult owner's manual for proper "Replacement" intervals or just the "Inspection" intervals. Just as an example, transmission oil is recommended to be "replaced" at 55k kms according to the owner's manual and it is suggested to get it "inspected" at 40k kms.
In future, please stick with the owner's manual for changing fluids, although it's not bad at all to change it early, if you get it changed now just to have a peace of mind while buying a new car, then you end up in spending more money which is simply not required.
One last thing which I want to share is that I have got an experience of a lifetime that never ever go to Toyota dealership for the maintenance of your car as they will rip you off and if you have less knowledge about car maintenance, then be ready to spend a lot on the suggestions of "Ustaad jee": "Ap gari ka yeh kaam bi krwa len, wo bi krwa len, aur phr befikr ho Jaen" and at the end of the day, you'll realize that the parts or things your car is not giving you any trouble before will start giving you trouble and you end up in spending more. Hope it helps.
Congratulations on the purchase by the way and enjoy your ride to the fullest, ALLAH naseeb karay. Aameen.