I've watched the first eight episodes, and they are very confusing for those who have never read the novel before. To understand the actual timeline of events, let me first explain their original profession in the novel - competitive gaming (aka, e-sports). Team Solo won championship playing a FPS (first person shooter) game, but they're basically legends in the entire e-sports world and not only among FPS games fans (and Solo thus moved to playing other games professionally after their team broke up). After K&K and SP were established, they basically have teams for every "famous" game possible (some actual games that were featured are Dota and LoL). The team that Wu Bai leads as the leader is a fictional FPS game that's supposedly very similar to the game that Team Solo won championship for.
Based on what I've remembered, this is timeline of events:
#1: The era of Team Solo. Team Solo breaks up after getting their championship (as shown in Go Go Squid).
#2: The Singapore league. Ai Qing meets Wu Bai and forms a friendship with him (sort of). She participates in a not-very-popular solo game (Need For Speed) because she couldn't place in a popular solo game (I think it was Starcraft?). Solo (as in, her ex-boyfriend) was highly ranked in Starcraft and was there representing China too. Grunt was introduced here too as Solo's diehard-fanboy who wants to beat Solo in Starcraft. Wu Bai was in a team game (Dota, if I didn't remember wrong). SP/K&K was not established yet here. Wu Bai was still a minor here and Ai Qing was hardly 20? I believe Wu Bai simply idolises Ai Qing and holds no romantic feelings for her here yet.
#3: Ai Qing retires from e-sports. She meets Hua Ti (as shown in the drama), who has a hand injury. I forgot how she ended up signing with Team SP, but it's around this time too.
#4: Years later, Ai Qing is the coach for one of SP's FPS game team. Wu Bai leads one of the teams of K&K for the very same game. They meet again as competitors. This is also where Han Shangyan and Tong Nian meets.
Go Go Squid actually does a pretty decent job of summarising Books 1 & 2 (that were what those flashbacks were for). I think the production team did not expect the drama to be such a huge hit, and to be making a spin-off for Books 1 & 2, else they'd probably have toned down on the backstory. I'm not sure how they're going to try to make the events/timelines work now, but that aside, many scenes have been true to the book thus far. How they're being executed, however...
Anyways, hope it helps! I may be wrong for some parts though as it has been a while since I've read the books!