For your current situation, I'll give some of my "e-advices"
First, you can try read this helpful
guide to familiarize yourself with skyblock.
1. Quick money? (But safe of course)
[Do note this doesn't apply on all situation. When a season just started, noone have farm or profit shops yet, so you can't use this method, except the begging part. Did I said begging? Don't worry about it]
If you got a diamond sword from vote crates.....(or swords from /kit ) do
/is top and right click on the #1 island to warp there. There, you can kill some epic blazes or epic villagers (or other mobs) for 1 or some minutes, then sell the loot in
/shop>Prestiged Loot Right click on an item to sell the same items you have. There, you should at least get some thousands of money. You can keep doing that until you feel ready for the next step.
The alternative?
Of course, asking some money from other players. You might think it's not a polite or hardworking way to begin with, but trust me there are plenty of players out there helping new players with some thousands of money, it's not a big deal. If you got some money already, you can visit a cactus profit farm then start reselling cactuses from there. To check if someone have cactus profit farm, you can ask in the chat, or do
/is top and right click on each island to check if there's a warp named "Cactus" or "Profit", then warp there. Right click on the sign to buy the cactus, then sell it on
/shop>Food&Farming and right click on cactus icon.
2. Casual gameplay.
No need to be hurry, just join or make your own island, the start progressing. Things like making cobble generator, expanding island, making a nice small farm of crops or trees, and finish the missions in
/level to unlock more features and some rewards. For money, you can get from selling loots from cobble generator, selling woods, or selling the crops you harvested. Plan your island or read some useful tips and guide on forums and rules if you are afk'ing your farm.
For starting, that's the 2 method I can think of for your current situation. The next steps will make my "essay" even longer, so I'll just pin some links to some useful tips and guides on later on if you like. Hope this helps.
Enjoy playing on SBD, and good luck!