Here is the first screen you should start with to setup WSJT-X, the Settings page. Your amateur radio callsign and grid square are the minimum requirements. Most of the other settings should be self-explanatory.
Not show are the Radio and Audio tabs of the Settings menu. Those are specific to your equipment. You will need to know the COM port your radio uses (if you are using computer control or CAT), as well as selecting the sound card interface. Note that you should define a default sample rate of 48000Hz 16-bit or better, for your audio device. Do not select the sound card used for your normal computer sounds!
In the Mode dropdown menus show below, you will see a list of the many modes incorporated into WSJT-X. Some users may only use one mode, while others will use several.
FT8 is especially useful for 50 MHz (6 Meter) fast Es openings lasting for a short period of time.
JT4 is designed especially for EME on the microwave bands, 2.3 GHz and above.
JT9 was originally designed for the LF, MF, and lower HF bands. Its submode JT9A is 2 dB more sensitive than JT65 while using less than 10% of the bandwidth. This means that a much larger number of QSOs can occur in the same frequency range as a JT65 signal.
JT9+JT65 as shown with the blue box, are two modes which are primarily used on HF. On the HF bands, world-wide QSOs are possible using power levels of a few watts (or even milliwatts) and compromise antennas.
JT65 by itself is actually JT65A, and is the narrowest version of JT65. It is commonly used for 6 meter EME. It is also used on HF with rigs having a limited (< 3 KHz) IF passband where mixed JT9+JT65 operation is not possible or is not a priority.
QRA64 is a newer 'experimental mode' for EME.
ISCAT, MSK144, and optionally submodes JT9E-H are “fast” protocols designed to take advantage of brief signal enhancements from ionized meteor trails, aircraft scatter, and other types of scatter propagation. These modes use timed sequences of 5, 10, 15, or 30 s duration. User messages are transmitted repeatedly at high rate (up to 250 characters per second, for MSK144) to make good use of the shortest meteor-trail reflections or “pings”. ISCAT uses free-form messages up to 28 characters long, while MSK144 uses the same structured messages as the slow modes and optionally an abbreviated format with hashed callsigns.
WSPR (pronounced “whisper”) stands for Weak Signal Propagation Reporter. The WSPR protocol was designed for probing potential propagation paths using low-power transmissions.
Echo mode allows you to detect and measure your own station’s echoes from the moon, even if they are far below the audible threshold.
Additional technical information on the various modes can be found here.