Get a ryoba handsaw right now
I've tried a few times to make useful yet portable things out of wood and never really succeeded. To cut a long story short, what I never realized was that handsaws sold in home improvement stores are worse than useless, and all I needed to do was get something else.
The Gyokucho Ryoba Saw - itself $20 or so at Amazon - changed everything for me. Instead of crude, difficult, frustratingly slow cuts irrespective of grain, it glided through so easily that woodworking became instantly fun and creative instead of a grueling waste of effort.
To woodworking naifs like myself, the Japanese design might be alarming at first: you cut on the pull instead of the push, and (at least on this type of saw) there's a second set of teeth instead of a reinforced back. One set's filed to rip with the grain, the other to make crosscuts. I got used to it in moments, and so will you.
I'd almost forked out $100 on a fancy backsaw, but I doubt I'll ever need something like that now even if I spend the rest of life sawing random lengths of wood in my garage.
The first things I've made: a workbench, two radiator covers and a new desk.
Woohoo! I know these are beginners' work, but these items are solid, stable, and exactly what I wanted. Dirt cheap too: perhaps $30 of wood each. (The $200+ cost of custom-fitting covers for big old radiators is what motivated me here).
Honestly this thing makes sawing wood so easy it's like playing fucking Minecraft. I'm mad I didn't get one sooner.
I'm sure someone will be along to inform me about why I can't do this or that important thing with one of these, but if you want to do woodworking but hate trying to, chances are this thing is the breakthrough you've been looking for. Get a steel square while you're at it.
Gyokucho Ryoba Saw [Amazon]