Hi and welcome back to the hobby! I had to go back to basics after only 10 year gap and it was a bit of a steep learning curve... I would suggest you go for 100litre/25 gal tank, bigger one if you can.
The choice for fish is huge nowadays, I'd suggest you get a good encyclopaedia of tropical fish, see what tickles your fancy and then do more research online whilst the tank is cycling. I love my community tanks so for a 80 cm (eg Fluval roma 125/Juwel Rio 125) tank:
10 glowlight danios (Danio Choprai)
Pair of kribs (Pelvicachromis Pulcher)
6 cories
1 Bristlenose plec
or
10 harlequin rasboras (Trigonostigma Heteromorpha)
6 otocinclus
8 Dwarf loaches (yashuhikotakia sidthimunki)
Or... The choices are limitless, just read read read. Gouramis, small plecs, dwarf cichlids, biotopes, planted or non planted tank, tetras, barbs... You have a lot of decisions to make.
