Looking back at the https://vgforums.net/t/compilation-of-all-patch-notes/647, that was almost exactly a year ago, believe it or not! Silvernail came out in 3.6, last August. We’re in 4.5 now, and have had a bunch of new heroes since you last played: Yates, Inara, Magnus, Ylva, San Feng, Caine, Leo, Warhawk, and Miho. Of those, Yates is a strong meta roamer that you might try, and San Feng is actually really good in that role too, if slightly off-meta and situational. Maybe meta, even, depending on who you ask.
Some of the big changes since you last played came in 4.0: Minion Candy, Nullwave Gauntlet, and Ironguard Contract were removed. Ironguard is probably the most important change, and pushed healing roamers (Lyra, Adagio) into greater relevance, and helped cement roamers as mid-lane supports. The contracts now build out of Oakheart 
, as T2 items, and as part of Rook’s Decree 
, in the case of Protector Contract 
, and Shiversteel 
, in the case of Dragonblood Contract 
. I don’t think many folks are using those as part of an early game strategy anymore, but I could be wrong.
Another big change is Stormguard Banner 
no longer dealing extra damage to non-jungle monsters/objectives (happened in 4.1), and it procs like tensionbow now, on a timer, so it’s meant as a jungler item and not a supplement to roams, generally.
Another change - jungle monsters no longer give ambient gold (and experience, I think?), so there’s even more incentive for supports to assist lane, typically mid, which has more gold than the side lanes.
For tips on specific roam heroes, you might check out the guides (or request one, actually). We’ve got a comprehensive one for Catherine (Catherine: Builds, Playstyle, and Discussion - #10 by Lebatron) and a pretty good one for San Feng (San Feng: Builds and Playstyle Tips), [edit to add: And Lyra!], but we def need some more roam guides. Maybe Yates would be a good one to start… I’ll get on that.
You might also check out idmonfish’s 5v5 overview for a refresher (still relevant!): 5v5: A Year On - Strategy where are we now?