Welcome on Bicycles. Your two reasons "The reason I want to try it is, even on flat roads, I am maxed out of gears and still dont achieve descent casual speed like other Hybrid bike riders. And it is also not helping on climbs." seem to go against each other to me.
I understand that you want a larger crankset. That would achieve higher possible max speed if the cadence is kept constant*. It would make hill climbing more difficult. 50-34 is rather a road bike crankset, hybrids or trekking bikes often use lower ones. Your frame may be quite likely not have the required clearance for such wide chainrings.
*The cadence is important, many beginners just rotate their legs too slowly. If you want to ride fast on the flats, be prepared to go for 100 rpm if you cannot get a harder gear.
"Similar thing with the CASSETTE." It is very unclear what you want to do with the cassette. If you want to increase the range of gears you must follow what your derailleur allows.
BUT - your bike does not have a cassette at all. It has a 7-speed freewheel. It is an option for very cheap bikes. What you can do without changing the hub or the whole wheel is extremely limited.
Honestly, I do not think it is worth investing too much into this kind of a bike. Changing the drivetrain would be too expensive. Rather, look for some better bike. Something that you try before you buy, where verify that the possible change of gears is good for your use. Modern MTB bikes can have a wide range of gears even with just a one chainring. Or get a hybrid with two or three chainrings. Look for bikes with a real cassette, also to avoid breaking the rear axle. 7-speed freewheels are prone to such breaking. 9-speed is probably reasonable minimum today for the number of speeds in the rear for these kinds of bikes. For a road bike, 8 can be enough for beginners.
If you do not have enough money for a new bike, look for a second hand one or ride what you have. As I wrote, I would not invest any significant sum into this bike.