You will need to select a location for your chime unit. There are two factors to consider. (1) The unit needs to be in a location where it will be heard. (2) It will also need to be a location that wiring can be run to it, or, already has wiring installed.
The wired doorbell that you buy will come with a set of installation instructions. Choke back the desire to proceed without reading them. There will be some key points that you want to take note of.
The first step or an early step will likely be mounting the chime unit. Generally you mount them high on the wall in a location where it can be heard. Being able to hear your doorbell is important for obvious reasons. Putting in an obscure location where you won't be able to hear it is not wise.
The instructions will likely have some guidelines on how to place it in relation to the buttons. Decide on a location and then you are ready to install it.
Wired doorbells do not weigh very much so, in wall backing is usually not required. Some type of plastic shield will likely be provided with the doorbell. You should get a template for the hole pattern with the unit, but not always. You may have to measure the mounting holes on the base plate. Use a level when you lay out the holes
With the holes laid out you can use a drill to put the anchors in. Once you have the anchors installed, you can set the base plate. Mount the base plate as directed. This is the hardest part, once it is done you can relax.
Instructions may vary, but you will likely want to make sure you have the batteries in at this point. You will not be able to test the wireless doorbell without the batteries.