Some items in developing kits I've seen are rather superfluous,
and some important items may not be included.
For less money you can assemble your own kit.
IMO for 35mm film at minimum you will need:
- Changing bag
- Developing tank with reel(s)
- Film clips for drying - two per reel (one weighted)
- Airtight opaque containers for chemical stock solutions - quart and pint sizes (2-3 each)
- Graduates - large and small sizes
- Funnel - should fit neck of developing tank
- Thermometer - should fit neck of developing tank
- Long stirring paddle
- Good scissors - long thin and straight
Paterson tanks and reels are ubiquitous and serviceable.
However I prefer the AP deluxe plastic tanks and reels.
IMO they are well worth a few more dollars/pounds/euros.
I also recommend you get a larger size changing bag.
The smaller size are difficult - and sweaty - to work in.
Assuming you will be developing factory loaded film
you will need something to open the 35mm cartridges.
A household bottle opener works fine for this purpose.
Your watch or smartphone will suffice as a timer.
Later you will add other items for convenience,
but you can make a good start with the above.
Good luck,
Chris