There are cheap compression testers that just have a tapered rubber tip that you hold in position. They are not advised for your application. Get one with various thread adapters so that it can be screwed in. Some models hold the peak measurement and release the pressure using a button. They are better for one person.
You should also get a remote starter button. Cheap is OK. It has clamps on its leads that you attach to the battery lead and the starter solenoid terminal to enable you to press a button to engage the starter. Do not test with the ignition on.
I against my better judgement do buy some Harbor Freight tools for jobs that I won't be doing many times. They are OK not professional though.
My rule in the past was to only buy good tools that would last a lifetime. Now at my age, that operational period has gotten shorter