If you are just getting started, here are a few suggestions to keep things easy for you.
1. Never use any sort of fluid to start your fire no matter what you are burning. Easiest way to start a fire is with a charcoal chimney. A wad of newspaper in the bottom..fill the chimney with whatever you are burning..(Charcoal, lump, wood chunks) Light the paper and let it go until the chimney is like a jet engine with everything inside burning nicely...then dump in your firebox (quickly and carefully)
2. Choice of burning material...
You can realistically cook with anything in your offset once you gain experience.. I would suggest you start simple, then move to more difficult materials as you feel comfortable...or begin looking for a new challenge.
The easiest thing to cook with in an offset is plain old charcoal... do not use any that is enriched with starter fluid...like matchlight.. Stubs is a good natural brand...and the higher end kingsford. If it smells like lighter fluid..pass on it..You can add a few chunks of wood for flavor, but even without..you'll get some smoke flavor and a nice smoke ring.
Next thing to move to would be lump charcoal. The advantage of lump is that is is pure pre-burned wood. Most brands I've seen are a nice mix of Oak, Maple, and Hickory. You won't really even need to add any thing else for flavoring..the wood flavor is built in. The disadvantage of lump is that some find it difficult to control the temp. But once you master controlling the heat with lump, you'll never go back to briquettes.
Next would be stick burning..which is not exceptionally easy in a smaller offset. The advantages are obvious..you are cooking with true wood and there is no substitute for wood. The downside is that if you thought lump was tough, wood is even tougher for a beginner. Two options..one is preburning you wood in another container which makes maintaining temp easier, but adds a whole new process and you really have to be on top of it so you have your wood pre-burned and ready when you need it. .. The other option is just burning the wood directly in the firebox..while this is one process, keeping wood burning clean in a small firebox without driving your temps too high can be tough for experienced smokers.
Use a charcoal chimney to start for fire.
Start with charcoal briquettes and work you way up as you go.
The higher up the fuel chain you go, the better tasting and more satisfying your smokes will become.