HOW TO MAKE A MASHUP IN ONLY 3 MINUTES (Audacity)

Find acapellas and instrumentals on YouTube, there are thousands. Just look up the song you're looking for and there should be at least one! TOOLS YOU CAN USE ARE TOWARDS THE BOTTOM OF THE DESCRIPTION.
THANK YOU FOR ALL YOUR SUPPORT!

Tools:

BPM tool - all8.com/tools/bpm.htm
tap using a keyboard along with the bpm and it will give you a bpm number to use. I use this VERY often.

BPM Search - songbpm.com/
Type in the name of a song and it will probably come up, useful if you are unsure in your ability to tap out the BPM with the other tool.

Audacity - audacityteam.org/

Instrumental Database - hipstrumentals.com/
Lots of instrumentals, original and remakes.

Old 10 minute tutorial (probably more in-depth): youtube.com/watch?v=IMFn_8wVtVw

Background Music is made by myself, it's a remix of Small Shock in the Undertale OST. (Custom made, not a mashup)