I very rarely use Community Applications to install containers on my server. Actually just today I finished making another container and getting it running on my server.
If you can find a Docker container on Docker Hub, you can most likely get it running on unRAID with no issues. To setup a new container, just follow a few steps and you shouldn't have many issues.
Read the official Docker container documentation very thoroughly. Seriously, I can't tell you how many times I've failed to get a container started because I missed a parameter, or how many containers I've skipped adding a volume to only to find out no config saved after a restart.
Go to your Docker Tab in unRAID and click Add Container
Leave the Template blank. unRAID will create a template when you get your container running
Give it a name- not like Bob or Sally, but a name which is basically what the container is. Plex, LetsEncrypt, etc.
In Repository, enter the Docker Hub repository along with the tag, eg. homeassistant/home-assistant:stable where stable is the tag. Docker Hub is good about telling you the Docker command to run the container, you just don't need the docker run portion in this field
Network Type is where things can get tricky. Host shares the IP with the server. Bridge gives the container a unique IP address within the private network of Docker. Most of my containers use Bridge. If you want to get really technical you can create Docker networks. My Home Assistant container runs on a network I created that is on my smart home VLAN.
If your container requires a PATH, and if you plan on saving data it will, click Add another Path, Port, Variable, Label or Device and in the dropdown select Port.
Name is human readable only and I've played with a lot of different naming conventions, but I just stick to the container path without the leading slash, so config for example.
Container Path is the path the container needs, so for my HA container, it's /config
Host Path is the path on your unRAID server to store the data, so for my HA container, it's /mnt/cache/docker_stash/homeassistant/ and as you can see I've created a folder that only exists on my cache drive for Docker. This is unnecessary but I was using a small 15k drive when I created this and didn't have much space for anything other than my Docker container on the drive. This was just a workaround and I'll eventually move it all to another folder
If your container requires a PORT, click Add another Path, Port, Variable, Label or Device and in the dropdown select Port
Name is human readable only, but for the most part I just make it the port number. Sometimes I'll specify that it's for, like Web UI but that's rare
Container Port is the port the container needs opened which will be in the container documentation
Host Port is the port you want to direct this to on your unRAID server. If you have a container that needs port 80, this is where you would redirect to 81, 8080, etc.
Connection Type is either TCP or UDP. Again the container documentation will tell you and if it doesn't, assume TCP. If it doesn't work, edit the container and try UDP.
If you need more settings than you can access with the Add another Path, Port, Variable, Label or Device, then in the upper right you can toggle the switch that says Basic View and get into Advanced View. From here you can specify the Docker Hub URL, Icon URL and even the WebUI which for Home Assistant is http://[IP]:[PORT:8123]/lovelace. So you see you can do the IP, port and even a path all in here so you can easily access your UI from the main unRAID screen. Extra Parameters is where odd things go, such as on my Home Assistant I'm skipping my Pi-Hole container with --dns=1.1.1.1 to tell the container to use Cloudfare's DNS.
As you can see, you have quite a bit of flexibility and power with unRAID. When I first got in and was learning about running Dockers on unRAID it sure seemed narrow minded just to limit myself to only the Community Applications and I wanted to figure out how to do it on my own. If there is already a Community Application that gets me there, I'll use it but I don't want to be limited to only that one place when there are so many containers. Also, the beauty of Docker is if 100 people make containers for something like Plex or Home Assistant, you can always switch your Repository if the one you are using isn't keeping current and just save your settings. As long as they aren't doing some weird stuff for their container, you shouldn't have to change any ports, paths, etc. and it should just work.