I am new to fish keeping and have never owned an aquarium before. I've been doing a lot of research on the topic but I would like some guidance on what fish I should be choosing. I don't want a fish that will be extremely easy to take care but I also don't want it to be extremely hard. I'm thinking of getting a 75 gallon - 90 gallon tank.
Criteria
- Easy - intermediate to take care of
- Looks good
- Active
My first tanks were 10 and 20 gallon tanks. I probably had 5 years experience before I owned a 55 and some cichlids. Unsurprisingly, I made a boatload of mistakes, lost a lot of fish, and realized that hands-on experience often counts for a lot. That all preceded my 55+ gallon-sized tanks.
According to your post, here's some of the basics you have never done:
1) started and sustained a nitrogen cycle
2) done regular and successful water changes
3) properly cleaned a filter
4) set up decor and a substrate
5) properly measured water metrics multiple times
6) addressed ich or other fish related diseases or parasites
7) handled an algae bloom
8) handled a bacterial bloom
9) determined lighting, feeding, cleaning routines
If I had a friend or relative who asked the same question, I would advise going with fish such as mollies, corydoras or guppies first, and not in a 75 gallon, but in a 10-20 gallon.
Worst case scenario: you buy the 20 gallon and you get bored. But you now have some beginners experience which will help towards a successful 75 gallon, plus you have 1) a tank which is set up and adequate to operate as a quarantine or hospital tank, 2) filter material which can be transferred to the 75, 3) better experience in understanding your interests and habits before choosing new fish, 4) potential experience with problems which you may have already seen.
In any case, I wish you luck in your experience and choices.