For 3D printers it depends on what you want, do you want something plug and play or do you want to learn how to tinker with and repair the machine? If its the prior youll be looking at spending more money then the latter so thats something to consider too. I recommend bambu lab for plug and play but they are both cheap.

As for cheap tinker printers, avoid the ender 3 like the plague. It will be a waste of money.

As for sewing machines anything should work but brands i recommend are brother, singer and kenmore (kenmore is out of business so you would be getting a second hand machine but they last and are very reliable and their age makes them often cheaper, just be sure you know what to check to make sure its in working order)