I have both ADSL (2.4) and VDSL (fiber- 5) connections at home. The home has structured wiring as well. The ONT ( Optical network terminal) is kept in the garage. I have connected the modem directly to ONT using an ethernet cable, so the modem is also in the garage. I wonder, due to this the internet speed is low upstairs where I have the master's bedroom and home office.
I also noted a signet cat.5e (? RJ patch panel ) in the garage. I assume that this is the starting point of RJ45 to all rooms etc.
My queries are as follows, please
1. can the ONT be connected to the modem in any other way or the modem should always be connected to ONT directly? I was wondering if the modem was kept in the main lounge or upstairs, I have better connectivity.
2. If modem and ONT to be connected directly, how can I improve internet connectivity and speed throughout the house in a better way?
3. I note signet cat 5e has many ports assuming each point needs a connection from somewhere. Is it from ONT or modem? Is it mean I should have separate ethernet cables for each area (the modem/ONT does not have that many ports). I also see the previous owner left a small red-colored ethernet cable, but I could not establish whether it should be connected to the modem or ONT. And what is the main use of it? Is it useful to have internet from RJ45 in each room using ethernet cable only?
couple of photos attached.

