Which tools to use for changing locks?
Congratulations on becoming a home owner.  You will soon learn to use lots of tools if you plan to do any DIY projects around the house.
Most locksets only require a #2 Phillips screwdriver. You should not need any special or expensive tools. Just read the directions and follow them. Changing locks is very simple, usually just two screws that hold the inner and outer knobs together and two screws that hold the striker cylinder to the side of the door. You may also have to replace the striker plates on the door frame, but that is also easy and has only two screws.  All the screws should use the same phillips screwdriver.  Good luck.