What wires are required for plugging in the Raspberry Pi?

[k-pi]

Your 5v power supply may not be supplying the correct power for the RPi - recommend using the official power supply.

P.S. HDMI ports on computers are not normally for receiving signals, only for sending.

(If you have the RPi set up for it, you should be able to access it via a cat5 cable.)

[mfa298]

What wires are required for plugging in the Raspberry Pi? The green light next to the red light flashes about once every second

That sounds about right. The red LED is power and should be on all the time, the green LED is Activity and should blink with activity (should be configurable within the OS).

I have an ethernet cord, hdmi cable, and micro usb port plugged into a 5V power block. The Pi will not show up on my macbook but will show up on a separate monitor.

How are you connecting those cables and what are you expecting to see? The Pi is a small computer so think of it as any normal computer when you connect it up.

[DougieLawson]

The red LED flashing can be a sign of trying to boot a 3B+ with an SDCard that isn't 3B+ ready.

So grab a new SDCard, grab a copy of plain Raspbian, grab a copy of Etcher. Use Etcher to write Raspbian to the SDcard.

[jbudd]

The red LED flashing can be a sign of trying to boot a 3B+ with an SDCard that isn't 3B+ ready.

Your 5v power supply may not be supplying the correct power for the RPi - recommend using the official power supply.

What in the original post makes you think the power supply is inadequate, or that the red LED is flashing?

There are two ways to use a Pi - with an HDMI monitor and USB or wireless keyboard and mouse or "headless", using another computer to connect and access.

You are not clear which of these you prefer. You do mention an HDMI monitor. To interact with the Pi on the monitor, you need to connect keyboard and mouse.
For headless operation you need to enable SSH by creating an empty file "ssh" in the small FAT32 partition of the SD card. This approach is not easy if you started with NOOBS.

There are various ways to identify the Pi on your network. Fing on a mobile phone, Angry IP Scanner on your Mac, the DHCP client list on your router admin pages, etc.

[davidcoton]

The red PoWeR LED should be continuously lit.
If it flashes a pattern, this usually indicates an out-of-date os that must be updated/upgraded before it will work on a Pi3B+
If it flashes off at random, that indicates an inadequate supply. The recommended supply for a Pi3B+ is 5V1 2A5.

You cannot normally use the HDMI socket on a laptop as a display input -- it is output only.

You can use "SSH" or "VNC" to access a Pi remotely, without keyboard, mouse or screen connected directly. If this is what you want. look at the documentation on this site.
If you want to use eithe SSH or VNC over a wireless link, you will need to configure the wireless first. This can be done (like enabling SSH) by a file placed on the BOOT partition. Again, read the docs.