The headline of the first chapter is already a major roadblock:

第一回　甄士隐梦幻识通灵　贾雨村风尘怀闺秀

First Chapter / Act (第一回):

I identified 2 proper names:

• 甄士隐 Zhēnshìyǐn
• 贾雨村 Jiǎyǔcūn
  

So here is my try:

1. part: 甄士隐 has a dream/vision about the afterworld (?); in a vision he experiences / connects with the afterlife

2. part: 贾雨村 lives an ordinary life / life of a peasant (风尘) but dreams of / longs for (怀) the society ladies (闺秀 guīxiù)

Any other suggestions? If not I will continue with the actual story in the coming days - maybe it is easier than its title...

此开卷第一回也.作者自云:因曾历过一番梦幻之后,故将真事隐去,而借"通灵" 之说,撰此<<石头记>>一书也

My try:

此开卷第一回也.
Hereby starts the first chapter (but why the 也??)

作者自云:
The author (作者) himself (自) says/reports (云) .

因曾历过一番梦幻之后,故将真事隐去,而借"通灵" 之说,撰此<<石头记>>一书也

The novel "The stone recordings" was written due to the occurance of a dream that tells a story that hides real events and that tells about meeting the afterlife/world of the dead.

Components:

Because (因)
a former (曾) experienced (历过) dream / illusion (梦幻;  番 as a measure word).

故将真事隐去
the story conceals (隐去 passive with the 将) a true event (真事)

and reports how thereby/there (而借) a connection to the afterlife was established (通灵)

The book "The stone memories/recordings" was written

也 to finish the 将-construction

Any other thoughts on that?

It gets dramatic!

士隐听 了,也只得罢了.真是闲处光阴易过,倏忽又是元霄佳节矣.士隐命家人霍启抱了英莲 去看社火花灯,半夜中,霍启因要小解,便将英莲放在一家门槛上坐着.待他小解完了 来抱时,那有英莲的踪影?急得霍启直寻了半夜,至天明不见,那霍启也就不敢回来见 主人, 便逃往他乡去了.

My try:
士隐 heard this but could not do something about it. He idled and time passed quickly, then soon come the moon festival. 士隐 ordered the servant 霍启 to take (his daughter) 英莲 and go look for the festival. At midnight [霍启] heard nature calling (No. 1), and left 英莲 at the doorstep. By the time he finished his “business”, 英莲 was gone. Nervously 霍启 looked for her all night long – until after dawn. Then 霍启 did not dare to come back to his master and fled to another town.

Breakdown:

士隐听 了,也只得罢了
士隐 heard this (得罢了) but could do nothing about it

真是闲处光阴易过
(真是) Actually (闲处) idled and (光阴) time (易过) passed quickly

倏忽又是元霄佳节矣.
Then (倏忽) soon the (元霄佳节) moon festival came

士隐命家人霍启抱了英莲 去看社火花灯
士隐 ordered his servant 霍启 to hold (his daughter) 英莲 and go look for the (社火花灯) festival (performance and decoration)
社火 --> traditional art performance
花灯 --> decoration with flowers

半夜中
At midnight

霍启因要小解,
霍启 because he wanted to (小解 = 小便 = No. 1) get some relief

便将英莲放在一家门槛上坐着坐着
Therefore left 英莲 at (门槛) the doorstep

待他小解完了 来抱时,
By the time he finished his “business”

那有英莲的踪影?
Where is英莲? (where are traces of 英莲)

急得霍启直寻了半夜,
Nervously 霍启 looked for her all night long (half the night).

至天明不见,
Until (天明) dawn was not seen --> until dawn was over

那霍启也就不敢回来见 主人,
Then 霍启 also did not dare to come back to his master

便逃往他乡去了.
And fled to (他乡) another town