Depending on how big the house is, usually one wifi router (also called modem) is just fine. Using a wifi "strengthener" is not recommended as it actually doesn't help (you think you have full connection but its actually veeeerrrryyy slow). Alternatively, if you live in a big house (like i do), you may consider to make a 2nd router and place that in for example the 2nd floor. Of course you will need to route a cable from the "original" modem up to the router to get the internet connection. If you live in an apartment, i suggest you put the modem | router in the center so you have good connectivity in all corners of the apartment.
Also, as mentioned above, if there are no range issues, there will be no other issues connecting multiple...