Things you’ll be better knowing how to do in your garage rather than on the side of the road far from home are;

Truing your wheel
Replacing your break pads
Breaking your chain
What your tires PSI is
The weight limit of your bike
Repairing punctures.

We also look at a list of tools to bring on your first backpacking trip.

Gloves for cleaning
Spoke Key
Handkerchief
Puncture repair kit
Chain breaking tool
Wire Brush
Bike Oil