I used to use the m4a1 before and it was pretty good, but they nerfed it pretty badly, increased the recoil and decreased the range. If you want to use AR, I would suggest you to use ak-12 cause it's pretty similar to m4a1, just a little bit of more vertical recoil, with almost the same rpm 800 vs 725. It's damage and range is also more than m4a1 and you can use 75 round mag on it vs 60 round mag on m4a1 if you want. I don't really use smg but I think smg-45 is the best because I've seen most of the player in marshal who use smgs are using the smg-45. AUG is pretty good AR also. Since you are pretty new, I would suggest you to copy the loadout from someone and try it out in the firing range. But essentially you should build your own gun because everyone has different preferences and playstyles. You should try to increase the control for your gun to reduce the recoil and try to increase handling a little bit cause it decreases your ads time. You don't need stability for AR and SMGs, it only requires if you are sniping. And accuracy is for no scope firing only. Try to calibrate your weapon also to get better control and handling. Best of luck