How to keep the response packet after filtering http in wireshark?

For example, there is a file name a.pcapng,

Ireshark -Display Filter to Show Packet # in “gtpv2.response_to” Header

Using WS 4.2.5

Cannot install downloaded Wireshark

I downloaded Wireshark on my desktop but cannot open it in Notepad – screenshot is enclosed

Wireshark TCP RTT

How can analyze this graph? Is about a file download lentancy. I can not understand the final part, why do like that. If can exploain all I appreciate.

How to filter for HTTP traffic with a specific URL via Wireshark?

I am new to wireshark and I would like to achieve the following: