I forgot to include these other sentences I'm not sure of.

1) I joined the Scouts in 1990. I went on a summer camp with the Scouts in July.
2) We camped in the mountains. We put up our tents as soon as we got there.
3) In the evenings() we made bonfires and sang music on our guitars.
4) We spent the whole day hiking in the mountains. We also played hide-and-seek and blind man’s buff.
5) I’m a literature fan. I like reading books. I also like lying in the sun on a sun-bed or a deck chair.

1) I went to a summer camp . . .

3) In the evenings, . . .

Everything else is correct.

To incorporate the additional sentences into the existing context, you can revise the paragraph as follows:

"I joined the Scouts in 1990, and in July of that year, I went on a summer camp with them. We camped in the mountains, and as soon as we arrived, we put up our tents. In the evenings, we made bonfires and sang music while playing our guitars. During the day, we spent our time hiking in the mountains, and in between, we played games like hide-and-seek and blind man’s buff. Besides my involvement with the Scouts, I'm also a literature fan. I enjoy reading books and soaking up the sun on a sun-bed or deck chair."