SMD components have been around for a long time but for the most part I have been able to get away with just using through hole parts. However more and more parts are only available in SMD form factor so you may as well get on the SMD bandwagon.
You can solder the SMD parts (least the larger ones) by hand but it can be difficult. One of the easiest options is to use solder paste and a hot air reflow tool. These tools typically consist of a wand with a heater element and blower connected to a power supply with a speed and temperature controller.
To solder a SMD device you apply small dabs of solder paste on each pad, place the component on the pasted pads, apply heat with the reflow tool until the solder melts.
While this works when soldering a small number of parts and is great for repairing existing solder joints it can get tiring to do a complete board. A better tool is a reflow oven. For this you paste up the complete board, place all the components and place in the oven. A few minutes later your board is soldered up.
There are various options for building a reflow over using a small toaster oven. I’m going to cheat and link an Instructable article I did a few years back rather than rehash it all here (I’m lazy). The Instructable goes over both fabricating the oven (in great details) and using it to solder PCBs
Of course now that you have an oven you may want to find a quicker way to apply the solder paste. Using a manual plunger will get the job done but your hand will get very very tired. Stencils are an option but can add cost and you have to be able to make one or get it with your PCB. I elected to use a pneumatically operated glue dispenser. These are available reasonably cheaply from China. Again I’ll link the existing Instructable I did a while ago that covers fixing, setting up and using the dispenser for solder paste.