Just tried first brew...

I brewed a Hefeweizen. Let it ferment for 3.5 weeks, then tried it after 5 weeks in the bottle.

I didn't do FG and OG, because I forgot to sanitize the hydrometer

Smell- Doesn't smell great - smells sweet, homebrew-y like the other home brews Ive tried. I don't really know how else to describe it.

Pour - It has carbonation, bubbles etc. Good

Taste - Tastes pretty good! Way better than I expected given the smell. It does taste a little homebrew-y, but not that much, tastes decently like a hefeweizen.

The biggest problem with the brew was probably the fermentation temperature - it was high, which is why I brewed a hefeweizen.

Well congratulations on your first batch.
You can lower the temperature pretty easily with a plastic pale, a little ice, some water and a towel or t-shirt. And if you get it really cold for a day or two before bottling, it can really help clear it and lessen the yeast.

You don't need to sanitize your hydrometer. When racking, pull off a separate sample for taking your measurements and then *don't* pour it back into the beer when you're done. Drink it instead!

+1 on drinking the sample. I hardly even wash my hydrometer, to be honest. Just give it a good rinse as soon as I'm done and call it good. I wash and sanitize my wine thief every time though since that makes contact with the beer in the fermenter.

Temp could be where the smell is coming from. Get that under control on your next batch and you might be a little more satisfied with the product.

You don't say how you made your brew.
If you used a kit and added a lot of sugar to make up for a lack of fermentables contained in the kit, then that is where you might be getting your " homebrew" taste.
Adding a lot of sugar tends to give a cidery taste which people associate with homebrew.

I used DME, Wyeast liquid yeast and 4oz priming sugar - I bought the kit at a Morebeer store.

Is 4oz for 5 gal too much? This is what the recipe suggested and your homebrew wiki suggests, and John Palmer as well.