This'll be a rundown of the main players and what's at stake here. It's been 9 years since the last elections, so a lot is at stake.
Lebanese politics operates on a confessional system, meaning the electoral system is set up based around ethnoreligious lines. 50% of the seats in parliament are for Christians, 50% are for Muslims and Druze. Within these there are also subsections, from Maronites and Armenians to Sunnis, Shia, and so on. Most of the parties tend to represent a singular demographic, despite also drawing some support from other groups. The Prime Minister must be Sunni, the President Maronite, and the Speaker of the House Shia. This is all due to France's colonial legacy, as well as the Taif Accords that ended the civil war.
The main parties:
Future Movement: Lead by PM Saad Hariri, son of former PM Rafic Hariri. Mostly Sunni. The Hariri family is among the richest in Lebanon, which is how Rafic got into politics. FM is/was part of the (now mostly defunct) March 14 alliance, which was created to oppose both Syrian intervention in Lebanon and Hezbollah's armed power and influence.
Free Patriotic Movement: Lead by foreign minister Gebran Bassil, son in law of President and former party leader Michel Aoun. Predominantly Maronite. Aoun was an important general during the civil war and was able to build his political career off that, after he returned from exile. FPM is part of the March 8 Alliance, which supports closer ties with Syria.
Amal: Lead by Speaker Nabih Berri. Largely Shia. Amal was the first major Shia militia set up during the war, created by Musa al-Sadr. After he disappeared, Berri took up the reigns and has lead the party ever since. Also part of March 8.
Hezbollah: Lead by Hassan Nasrallah, who holds no political office. Largely Shia, of course, and the most important party in Lebanon due to their armed wing, which is more powerful than the Lebanese army. It was the only militia allowed to remain armed after the Accords, which has caused much contention. Still, they've cemented their position some, and especially after the whole Hariri kidnapping thing, even their political opponents have come to respect them for their commitment to Lebanon. Politically, Hezbollah is interesting because they've pushed against the status quo, advocating for an end to the confessional system and increases in welfare. They're also the only major party not widely seen as corrupt and paternalistic. Still, they've not pushed for this agenda much, as they see these types of politics as secondary to the resistance. Part of March 8.
Progressive Socialist Party: Lead by Walid Jumblatt, with his son Taymour leading it electorally. Almost entirely Druze, and despite the name, it is more a Druze party than some sort of movement for socialism (though one could make the argument it was in the past). They fought as part of the Lebanese National Movement in the civil war, alongside the Palestinians and the LCP, SSNP, and Baathists against the right wing Christian militias. They're unaligned right now, having shifting political alliances.
Lebanese Forces: Maronite, lead by Samir Geagea. Formerly part of March 14 until a split with FM. Split from Kataeb in the Lebanese Front.
Kataeb: Pretty similar to Lebanese Forces. Right wing Christians, except they also believe in Phonecianism, the idea that Lebanese Christians arent Arabs, but Phoenicians. An acquaintance described them as "Lebanese Hoteps" which I think is succinct. Were also part of March 14.
Civil society alliance: A coalition of parties, most of them quite new, have also banded together, seeking to upend Lebanese politics. They include the Lebanese Communist Party (which is quite old) but also Sabaa, YouStink!, LiBaladi and more. Their main targets are corruption and the sectarian system, and they aim to position themselves as apart from the two previous alliances. They came to prominence during the Beirut garbage crisis in 2016, and made some waves in the municipal elections there.
There's also a host of smaller parties, from Syrian Nationalists, to Sunni Islamists, to Armenian parties, to europhillic liberals, and more. Some of them are old, some are newer, some are ideological, some are based around single figures or families.
If you've noticed any trends, its probably that 1: Most of these parties don't seem very "left" or "right" and 2: Many look like they're based around familial ties. Lebanon is notorious for its corruption and many of the parties serve only as narrow vessels for specific ethnic groups. Most just follow a generally neoliberal path with the aim of only enhancing their own wealth and status. The issues on the table right now is mostly one of foreign policy, especially regarding Saudi and Iranian influence in the country, as well as the threat of Israel and the presence of Syria and its civil war.