To me, the biggest contrast between the effects of the two is that alcohol generally depresses the functioning of the brain while weed generally stimulates the functioning of the brain.
The other is that alcohol is processed through the body at the rate of about 1 standard drink per hour, depending on a lot of factors including age, weight, gender, ethnicity, etc, while weed can persist in the body for days, also depending on a lot of factors including age, weight, gender, ethnicity, etc.
As a creative person and scientist, my initial impulse upon reading your original post was to discourage you from trying alcohol if you haven't done so yet.
Anything more than very casual use (1 to 3 standard drinks over a 3 hour period) does no good for your brain. Heavy use can be damaging to the brain and other parts of the body.
In the interest of experimentation on the other hand, assuming you're old enough and responsible enough, I suppose it wouldn't hurt to try it.
There are certain advantages to depressing brain function slightly, such as for example if you are uptight when it comes to social interaction with people you might like to get to know better.
Unfortunately, that way too lies dependence if you're psychologically so inclined.
And if you do overdo it, there is this nasty effect of alcohol (which I've never heard of happening with weed) called a black-out, in which for lack of better description, most of the brain whose function makes us human shuts down and the body runs on a sort of primitive auto-pilot, completely lacking any form of censorship.
This can result in the person who blacks out
doing things they would normally never even consider doing and
not remembering any of it.
As with all mood-altering compounds, if you know when to say enough's enough, you should be OK. If not, you might not be OK.
Not trying to tell you what to do, but suggesting...
1. Give your vehicle keys to someone whom you trust not to return them to you under any circumstances until you're clearly sober again. It is never advisable to operate machinery while under the influence of any compound, prescribed or not. However, in my opinion, I would always rather be driven by a vehicle operator who is buzzed than by one who is drunk. Drunk driving is generally an unmitigated disaster while buzzed driving is not so much, in spite of what the authorities would like you to believe.
2. Don't drink in the presence of anyone who will reject you on the basis of whatever you might say or do while drinking and whose continued relationship you'd like to maintain, i.e. employers and other people who do not necessarily love you.
Other than that, I wish you luck.
BTW, if you're probably going to have sex or listen to music, you will completely defeat your purpose by drinking alcohol vs consuming weed. There is simply no contest there.